FTP
In plain terms
An old protocol for transferring files between systems.
Going deeper
File Transfer Protocol moves files between client and server over a network, but it's insecure since it sends data and credentials in plaintext. It's largely superseded.
Under the hood
No encryption; replaced by SFTP/FTPS for security in modern use.
Examples
Legacy file transfers, website uploads (historically), SFTP replacement.
Think of it like...
Like mailing documents on open postcards, anyone along the way can read them.