Keep in mind, that these are only the basics. Please refer to the Official Tails documentation.

Tails is a live-booted, debian-based Linux distribution, that routes all internet traffic through the TOR-Network. It can also be used in a Virtual Machine, but live-booting from USB is the recommended method. Tails uses GNOME as its main desktop-environment.

This way, Tails leaves no trace on the host system, as all data is stored in RAM.

One should ONLY use the Tails installation provided by the official sources! Official Tails Download

Even then, one should verify the GPG-Signature, to prevent using a compromised executable.

There are pre-installed applications like the Tor Browser, Thunderbird email client, and LibreOffice.