.txt: Plain text file
.doc / .docx: Microsoft Word document
.pdf: Portable Document Format, looks the same on any device
.rtf: Rich Text Format, text with simple formatting
.odt: OpenDocument text file
.xls / .xlsx: Microsoft Excel spreadsheet
.csv: Comma-separated values, a simple data table in text
.ppt / .pptx: Microsoft PowerPoint presentation
.key: Apple Keynote presentation
.pages: Apple Pages document
.jpg / .jpeg: Compressed photo image
.png: Image with lossless compression and transparency
.gif: Image format that supports simple animation
.bmp: Uncompressed bitmap image
.svg: Scalable vector graphics, sharp at any size
.webp: Modern web image format
.heic: Apple's efficient photo format
.tiff: High-quality image format
.psd: Adobe Photoshop file
.ai: Adobe Illustrator file
.mp3: Compressed audio
.wav: Uncompressed audio
.aac: Compressed audio format used by Apple
.flac: Lossless compressed audio
.ogg: Open audio format
.midi / .mid: File with music notes instead of sound
.mp4: Common video format
.mov: Apple QuickTime video
.avi: Older Microsoft video format
.mkv: Flexible video container format
.webm: Open video format for the web
.zip: Compressed archive of files
.rar: Compressed archive format
.7z: 7-Zip compressed archive
.tar.gz: Compressed archive common on Linux
.exe: Windows program
.msi: Windows installer
.dmg: Mac disk image used for installing apps
.app: Mac application
.apk: Android app package
.ipa: iOS app package
.iso: Disk image of a disc
.html / .htm: Web page
.css: Stylesheet for web pages
.js: JavaScript code
.json: JavaScript Object Notation, a common data format
.xml: Extensible Markup Language, structured data
.py: Python code
.java: Java source code
.class: Compiled Java code
.c / .cpp: C and C++ source code
.cs: C# source code
.php: PHP script
.rb: Ruby script
.sql: SQL database commands
.db / .sqlite: Database file
.md: Markdown text file
.yml / .yaml: Human-readable configuration data
.sh: Shell script
.bat: Windows batch file
.ini / .cfg: Configuration file
.log: Log file recording events
.tmp: Temporary file
.bak: Backup file
.dll: Windows dynamic link library
.sys: System file
.ttf / .otf: Font files
.epub: E-book format
.ics: Calendar event file
.vcf: Contact card file
.torrent: File used by peer-to-peer sharing software
File extension: The letters after the dot that suggest the file type
Filename: The name before the extension
Folder (directory): A container for files
Path: The location of a file, such as C:\Users\Sam\file.txt
Operating system: Software that manages a computer, like Windows, macOS, Linux, Android, iOS

Free flashcards from Peabody at peabody.kids/flashcards/tech-file-types-and-formats