Draw.io
In plain terms
A free, open-source diagramming tool.
Going deeper
draw.io (diagrams.net) creates flowcharts, network diagrams, and more, integrating with storage like Google Drive, at no cost. It's a popular free diagram tool.
Under the hood
Runs in-browser or offline; stores diagrams in your own storage, no vendor lock-in.
Examples
Flowcharts, architecture diagrams, free diagramming, network maps, UML.
Think of it like...
Like a free, full-featured sketchpad for technical diagrams.