How does it work?
With a regular (graphical) interface you click on buttons and menus. With a CLI you type a command into a text window instead, the terminal, and the program runs it. No buttons, just instructions in text.
That seems more awkward, but it has three strong advantages: it's fast, it's repeatable (you can save commands and run them automatically), and it gives a program direct access to your files and other tools.
A graphical interface is made for people who click. A CLI is made for those who want to automate.
Why does AI increasingly run on it?
The newest AI tools are no longer a chat window, but agents that carry out multi-step work on their own. Those agents often run via the command line, because that's where they come into their own:
- Access to your real work: reading and editing files, running programs, checking results.
- Automatable: a task that runs via the terminal can be scheduled and repeated, without anyone clicking.
- Connectable: via MCP, those CLI agents also reach your other systems. A well-known example is Claude Code: an AI agent that lives in the terminal.
Do I need to be able to do this myself?
No. The command line is today mainly the territory of developers and power users. As a user you usually work with the familiar graphical tools, while the heavy lifting often runs via a CLI behind the scenes. What matters isn't that you type commands, but that the automation runs reliably and is connected to your processes.
Related terms
- MCP: the open standard that lets AI (including CLI tools) safely reach your software and data.
- RAG: letting an AI answer based on your own sources.
- EU hosting and zero retention: where your data is processed and whether it's reused.
