What is ⌘ Cmd + A keyboard shortcut for?

Apple iBooks - Select all inline objects and text  

Apple iBooks - (Select one floating object and press Command + A) Select all floating objects  

Apple iBooks - Select all table borders or cell content, depending on the initial selection  

Apple macOS - Select All items  

elementary OS - Window overivew (across all workspaces)  

Roll20 - Select everything on current layer  

Waze Map Editor - Select Entire Street - mnemonic Select All  

Ace Editor (Mac) - Select all  

Adobe Acrobat 2017 (Mac) - Select or deselect all files  

TextMate - Select all  

Tomboy 0.23 - Select all items  

Typora 0.9.81 (macOS) - Select All  

Adobe Animate CC (Mac) - Select All  

Adobe Dimension CC (Mac) - Select All  

Adobe Illustrator (Mac) - Select all  

Adobe Lightroom Classic (Mac) - Select all photos  

Adobe Premiere Pro (Mac) - Select All  

Adobe XD (Mac) - Select All  

Apple iMovie - Select all clips.  To select all clips in the timeline, first click anywhere in the timeline. To select all clips in the browser, first click anywhere in the browser  

Autodesk SketchBook (Mac) - Select All  

Canva (Mac) - Select all  

Corel Painter (Mac) - All  

DaVinci Resolve 15 (Mac) - Select all  

Final Cut Pro X - Select all clips  

Final Cut Pro X - Select all clips  

Framer X - Select All Layers  

OmniGraffle 7 - Select all  

Pixelmator Pro - Select the entire image  

Xcode - Select All  

Xcode - Highlight every item in a document or window, or all characters in a text field (equivalent to the Select All command)  

AWS Cloud9 IDE (Mac) - Select All  

BBEdit 13 - Select all  

Coda for iOS - Select all  

CodeMirror - Select all  

CoffeeCup Web Editor - Select all  

Mode SQL Editor (Mac) - Select All  

Mode SQL Editor (Mac) - Select all  

RStudio (Mac) - Select All  

iTunes 11 for Mac - Select all the songs in the list  

QLab 4 - Select All  

QuickTime Player (macOS) - Select all  

Total War: Attila (Mac) - Select all  

Ableton Live 10 (Mac) - Select All  

Ableton Live 10 (Mac) - Select all Clips/Slots  

Abstract - – Toggle annotations  

Apple GarageBand - Select all  

Apple Pages - Select all objects and text  

Apple Pages - Select all objects  

Apple Pages - (after selecting a cell) Select all content in a table  

Final Draft 11 (Mac) - Select all  

Google Sheets (Mac) - Select all  

iPad Smart Keyboard - Select all text  

Melodyne 4 (Mac) - Select all  

Tableau (Mac) - Select all data  

Things (iPad) - Select everything  

Things (Mac) - Select everything  

Traktor Pro 3 - Select all  

GeoGebra - Select All