CompTIA Exam Prep - ITF+, A+, Network+, Security+, CySA+

APT — the Advanced Package Tool — is the package manager on Debian, Ubuntu, and their derivatives. It installs software, resolves dependencies, and keeps systems patched, and it is examinable territory on Linux+. A naming warning worth getting out of the way: in Linux, APT is a package manager. In security, APT means advanced persistent threat. They share nothing but three letters, and exam questions occasionally exploit the ambiguity. What APT Actually Does Underneath sits dpkg , the low-level tool that installs and removes individual .deb files. dpkg does exactly what it is told and nothing more — hand it a package whose dependencies are missing and it fails. APT is the layer above. It reads configured repositories, works out the full dependency tree, downloads everything required, and hands the packages to dpkg in the right order. Dependency resolution is the entire reason APT exists. The Commands Command What it does apt update Refreshes the package lists from the ...