In Unix systems, repositories are called source software, of which the package manager downloads and installs programs. The list of Debian (and its derivatives) is located in: /etc/apt/sources.list and files in the directory /etc/apt/sources.list.d/. The format of the file is:

Description:

• is kind of repository distinguish repositories of binary packages (deb), ready to use, and repositories of source packages (deb-src)
• repository address, it is usually http or ftp server can also be a local repository (file: //) or CD/DVD
• version used by our system, for example. Stable, testing, unstable. In most cases (in the case of official repositories always) may also be a code, for example: etch, lenny, sid
• packages group, for example. main (main section includes packages comply with the Debian Free Software Guidelines), non-free (contains the packages non-free), contrib (includes packages free, in line with the DFSG, but somehow depend on packages in non-free). Sections may be given in any order.

In sources.list file we can add one line:

This one allows to update and install new repositories for Kali Rolling users.

source.list

Why kali-rolling repository ? Answer from kali.org: In contrast to kali-dev, kali-rolling is expected to be of better quality because it’s managed by a tool that ensures installability of all the packages it contains. The tool picks updated packages from kali-dev and copies them to kali-rolling only when they have been verified to be installable. The repository is also fed by a stream of tool updates, of which we get notified via our upstream git tagging watch list.

After set up our repository in sources.list file we can easily update system by: