What is R?

Last reviewed Jun 1, 2026 Content v20260601

Track mode

server_script

Means

Server runner

Reading

~2 min

Level

beginner

This lesson

This lesson teaches What is R?: the syntax, patterns, and safety habits you need before advancing in R.

Teams still ship What is R? in R codebases—skipping it leaves gaps in debugging and code reviews.

You will apply What is R? in contexts like: Research pipelines, Shiny dashboards, and statistical reporting.

Write R in the editor and click Run on server—the dev runner executes with Rscript; use print() or cat() and base R in playground snippets (tidyverse locally; LEARNING_RUNNER_ENABLED=true).

After basic programming and ideally SQL—pair with Python for ML-heavy roles or stay in R for stats and research pipelines.

R is an open-source language for statistical computing and graphics, maintained by the R Core Team and a global contributor community. It runs as an interpreter (REPL) or via Rscript for batch scripts.

Core characteristics

Vectorized — operations apply element-wise; avoid manual loops when possible
Functional — functions are first-class; apply-family and purrr (local) iterate cleanly
Data-centric — data frames, factors, and formula syntax for models
Extensible — CRAN hosts thousands of packages for every analysis niche

Typical workflow (local)

Install R from CRAN; use RStudio or VS Code as IDE
Run Rscript analysis.R or work interactively in the console
Install packages: install.packages("dplyr")
Share reproducible reports with R Markdown (rmarkdown package)

Where R appears

Clinical trials, epidemiology, econometrics, marketing analytics, Shiny dashboards, and research publications. Compare general backends with Python or typed JVM services with Java.

Important interview questions and answers

Q: Is R only for academics?
A: No—pharma, finance, and tech analytics teams use R in production pipelines, often alongside Python and SQL.
Q: R vs Python for data science?
A: Both work; R leads in stats-native APIs and ggplot2; Python leads in ML engineering and web glue—many teams use both.

Self-check

What command runs an R script from the terminal?
Name one domain where R is commonly used.

Tip: R source uses .R files executed by R or Rscript—think stats-native analysis with CRAN extensions.

Interview prep

Is R open source?: Yes—R is GPL-licensed with source available from CRAN and community mirrors.
Who uses R?: Biostatisticians, epidemiologists, econometricians, pharma, marketing analytics, and research teams publishing reproducible reports.

Playground

Runs on the configured server runner (dev: npm run runner with LEARNING_RUNNER_ENABLED=true). Output appears below the editor.

Code runner not available

Server runner is disabled. Set LEARNING_RUNNER_ENABLED=true and LEARNING_RUNNER_URL in .env (see .env.example).

Discussion

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Starter discussion topics

R vs Python when?
CRAN role?

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