100% Free Forever
AI-Powered Learning
Industry Expert Content
Certificates & Badges
Learn At Your Own Pace
Programming

What Is R?

An introduction to R as a statistical programming language: its history, design philosophy, real-world applications, and how it compares to other data tools.

FoundationsBeginner7 min readJul 10, 2026
Analogies

What Is R?

R is a free, open-source programming language and software environment purpose-built for statistical computing, data analysis, and graphics. It was created in 1993 by Ross Ihaka and Robert Gentleman at the University of Auckland as an open reimplementation of the S language originally developed at Bell Labs, and today it is maintained by the R Core Team with contributions distributed through the Comprehensive R Archive Network (CRAN).

🏏

Cricket analogy: Think of how Mumbai Indians built a squad specifically for T20 chases under lights rather than repurposing a Test-match roster; R was engineered from day one for statistics in 1993, not adapted afterward from a general-purpose tool.

Why R Exists: A Statistics-First Design

Unlike general-purpose languages that require importing a library to get basic tabular or statistical capability, R treats vectors and data frames as first-class citizens from the start. Core functions such as lm() for linear regression, t.test() for hypothesis testing, aov() for analysis of variance, and plot() for graphics ship in 'base R,' so an analyst can fit a regression model and inspect its residual plot in a handful of lines without adding any external dependency.

🏏

Cricket analogy: It's like the DRS (Decision Review System) being wired directly into how umpires officiate a match rather than bolted on afterward — R's lm() and t.test() are built into the umpiring of data the same way, no separate kit required.

R in the Real World

R is heavily used in biostatistics and pharmaceutical research, including clinical trial analysis submitted to regulators like the FDA, as well as in quantitative finance, academic social science, and data journalism outlets such as FiveThirtyEight and the BBC's data unit. Much of this reach comes from CRAN, which hosts more than 20,000 peer-reviewed packages covering everything from survival analysis (the survival package) to spatial statistics (sf) to Bayesian modeling (brms).

🏏

Cricket analogy: It's like how Cricinfo's Statsguru tool is trusted by broadcasters, journalists, and analysts worldwide for the same underlying data — CRAN's 20,000+ packages give R that same cross-industry trust, from pharma to journalism.

R vs Python: Choosing the Right Tool

R and Python both dominate data science, but they emphasize different strengths: R's ggplot2 produces publication-quality statistical graphics with a concise grammar-of-graphics syntax, and its base statistical modeling functions are deeply refined for classical inference, while Python tends to be favored for production software engineering, web backends, and deep learning frameworks like PyTorch. Many teams use both, calling Python from R via the reticulate package or calling R from Python, rather than treating the choice as exclusive.

🏏

Cricket analogy: It's like choosing between a specialist spinner such as Ravichandran Ashwin for a turning pitch in Chennai versus a pace all-rounder for Perth's bounce — R suits statistical 'pitches,' Python suits production 'conditions,' and many squads carry both.

r
# A first taste of R: create a numeric vector and summarize it
heights <- c(165, 172, 158, 180, 175, 169)
mean(heights)          # 169.8333
sd(heights)             # standard deviation
summary(heights)        # min, quartiles, mean, max in one call

# base R already knows how to fit a model and plot it
weights <- c(59, 68, 54, 82, 75, 63)
model <- lm(weights ~ heights)
summary(model)
plot(heights, weights, main = "Height vs Weight")
abline(model, col = "red")

CRAN (the Comprehensive R Archive Network) is R's central package repository. Every package on CRAN passes automated checks and a human review before publication, which is why R users trust CRAN packages more than arbitrary code copied from the internet.

R indexes vectors and data frames starting at 1, not 0. Programmers arriving from Python, JavaScript, or C will instinctively reach for element [0] and get an empty result instead of an error, which can silently produce wrong analyses if not caught early.

  • R was created in 1993 by Ross Ihaka and Robert Gentleman as an open-source reimplementation of the S language from Bell Labs.
  • R is statistics-first: vectors, data frames, and modeling functions like lm() and t.test() are built into base R, not add-ons.
  • CRAN hosts over 20,000 peer-reviewed packages spanning survival analysis, spatial statistics, Bayesian modeling, and more.
  • R is widely used in pharma/clinical trials, biostatistics, quantitative finance, academia, and data journalism.
  • R and Python are complementary rather than strictly competing: R excels at statistical modeling and graphics, Python at production and deep learning.
  • The reticulate package lets R and Python interoperate within the same project.
  • R uses 1-based indexing, a common trip-up for programmers coming from 0-indexed languages.

Practice what you learned

Was this page helpful?

Topics covered

#Programming#RProgrammingStudyNotes#WhatIsR#Exists#Statistics#Design#Real#StudyNotes#SkillVeris#ExamPrep

Frequently Asked Questions

21 categories · pick one to explore

Where can I get free study notes for programming and tech subjects?
SkillVeris offers completely free study notes covering programming and tech subjects, with no signup fees or paywalls. The notes are structured by course and topic, written for quick understanding, and enriched with the Learn Through Hobbies analogy method, so you can revise concepts through cricket, music, gaming, cooking and more.
Are SkillVeris study notes good for exam revision?
Yes, the study notes are designed for efficient revision: each topic answers its heading immediately, keeps explanations concise, and links to related glossary terms and cheat sheets. Students preparing for university exams or certification tests use them as quick revision notes because they distil concepts without the padding of full textbooks.
What subjects do the free study notes cover?
The study notes span the platform's main domains, including AI and machine learning, Python and programming, web development, DevOps, cloud, security and databases. Coverage mirrors the 37 live courses, so notes exist for the topics you are actually studying, and new note sets are added as courses launch.
How are SkillVeris study notes different from regular textbooks?
The notes are answer-first, concise and free, whereas textbooks are long and often expensive. Each section explains one concept directly, then reinforces it through selectable hobby analogies like cricket or cooking. Notes also cross-link to the glossary, blog and cheat sheets, letting you jump to related material instantly instead of flipping pages.
Can I use the developer study material without creating an account?
The study notes are free to access, and SkillVeris does not charge anything for its developer study material at any point. Browsing notes is straightforward from the Study Notes section, and if you want progress tracking, certificates and AI Mentor conversations tied to your learning, a free account unlocks those extras.
Do the study notes explain concepts with analogies?
Yes, this is a signature SkillVeris feature. Study notes use the Learn Through Hobbies method, explaining technical concepts through analogies from twelve domains including cricket, music, gaming, photography, travel, movies, fitness, chess, cooking, finance, business and sports. You can switch the analogy domain instantly to whichever hobby makes the concept click.
Are the revision notes suitable for last-minute exam preparation?
Yes, revision notes on SkillVeris work well for last-minute preparation because every section states the answer in its first sentences, so skimming is genuinely effective. Pair them with the relevant cheat sheet for formulas and syntax, and use the glossary for any unfamiliar term you meet while cramming.
Is there free study material for AI and machine learning?
Yes, SkillVeris provides free study notes across its AI and ML catalogue, covering Python for AI, deep learning frameworks like PyTorch and TensorFlow, Hugging Face Transformers, Large Language Models, RAG, AI agents and MLOps. All of it is free, making it a strong resource for Indian students and global learners alike.
Can beginners understand the study notes, or are they for experts?
Beginners can absolutely use them. The notes are written in plain language, define terms as they appear, and lean on hobby analogies to make abstract ideas concrete. Difficulty scales with the underlying course level, so beginner-course notes stay gentle while advanced-course notes go deeper, and the glossary supports you throughout.
How do study notes connect with SkillVeris courses?
Study notes are organised by course and topic, so they map directly to the structured courses and their 24–40-lesson curriculum. Many learners study a lesson first, then use the matching notes for revision before module assessments and the final exam, where 80 percent is required to pass and earn the certificate.
Are there study notes for Python specifically?
Yes, Python is well covered through notes tied to the Python-focused courses, including Python for AI and ML. Topics span fundamentals through applied machine learning usage. You can reinforce the notes with Python practice in Code Lab, which runs code in your browser with no installation required.
Do the study notes include code examples?
Yes, study notes include code examples wherever a concept is best shown in code, alongside explanations, key points and analogies. Reading a snippet in the notes and then reproducing it yourself in Code Lab is an effective loop, since Code Lab lets you run code in the browser across six languages.
How often is new study material added to SkillVeris?
Study material grows alongside the course catalogue. Whenever new courses join the platform's 37 live courses, matching study notes, glossary entries and cheat sheets are added so the resources stay in sync. Existing notes are also refined over time, so it is worth revisiting topics you studied earlier.
Can I use SkillVeris notes to prepare for technical interviews?
Yes, the notes make excellent interview revision because they compress each concept into direct, answer-first explanations, which mirrors how you should answer interview questions. Combine them with the SkillVeris interview questions feature, which includes readiness scoring, to test whether your revision has actually made you interview-ready.
Are the study notes mobile-friendly for studying on the go?
Yes, the study notes are built to load fast and read comfortably on mobile devices, so you can revise during a commute or between classes. Sections are short and answer-first, which suits small screens, and analogy switching works on mobile too, letting you study anywhere without carrying books.
What is the difference between study notes and cheat sheets?
Study notes explain concepts in depth with context, examples and analogies, making them ideal for learning and revision. Cheat sheets are compact quick-reference summaries of syntax, commands and key facts, ideal once you already understand a topic. Most learners study the notes first, then keep the cheat sheet handy while coding.
Do study notes help if I am stuck on a course lesson?
Yes, reading the matching study notes often clarifies a lesson because the same concept is explained from a different angle, frequently with a different analogy. If you are still stuck, ask the AI Mentor, which answers 24/7 at Quick, Detailed or Deep-dive depth until the idea genuinely makes sense.
Is there free study material for DevOps and cloud topics?
Yes, SkillVeris carries free study notes for DevOps and cloud topics as part of its coverage across 37 live courses. The material suits learners following the DevOps Engineer or Cloud Engineer paths, and it links to related glossary terms and cheat sheets so you can revise the whole toolchain in one place.
Can school or college students in India use these notes for projects?
Yes, students across India and worldwide use SkillVeris notes for coursework, projects and exam preparation, and everything is free, which matters for student budgets. The notes explain concepts clearly enough to cite in project reports, and Code Lab lets you prototype the project code directly in your browser.
How should I combine study notes with other SkillVeris resources?
A proven loop: learn from a course lesson, revise with the matching study notes, look up unfamiliar terms in the glossary, keep the cheat sheet open while practising in Code Lab, and quiz yourself with interview questions. The AI Mentor fills any remaining gaps 24/7, at whatever depth you need.

What Learners Say

Real journeys from the SkillVeris community — swipe for more.

SkillVeris taught me Python through Cricket. Now I’m building real projects and feeling confident!
Arjun S. · B.Tech Student
The best platform for hobby-based learning. Concepts finally stick.
Priya R. · Data Analyst
I went from zero coding to a portfolio of projects — all by learning through my love for gaming. Landed my first internship!
Kabir M. · CS Undergraduate
Trending Topics50 popular tags — tap to explore
Trending CoursesAll 37 free courses — tap to browse