This TeX Collection (https://tug.org/texcollection) contains the
following software distributions:

MiKTeX   - a TeX distribution for Windows, macOS, and GNU/Linux.
           https://miktex.org (only the Windows port is shipped
           as part of this DVD)

TeX Live - a TeX distribution for GNU/Linux, macOS, other Unix, and Windows.
           https://tug.org/texlive

MacTeX   - a complete TeX distribution for macOS, containing all
           of TeX Live, but with a native Mac installer and other
           Mac-specific packages included.
           https://tug.org/mactex

CTAN     - a partial snapshot of the CTAN (Comprehensive TeX Archive Network)
           archives, containing everything redistributable, as uploaded
           by the authors. Large packages already present in the above
           distributions are omitted.
           https://ctan.org

You might well ask, which to use when?

- if you're a new user on Windows, MikTeX is probably the easiest
  installation. It can install new packages on the fly while TeX runs, a
  feature which nothing else has.

- if you're a new user on macOS, mactex is definitely the easiest
  installation.

- for experienced users wishing to simultaneously run multiple releases,
  or Unix users, texlive is the most common choice.

- ctan is there primarily for those without network access; it contains
  many more packages and programs, but they must be installed
  individually, and are not integrated with any of the distributions.

The TeX Collection is the product of thousands of individuals all over
the world, and the TeX user group organizations.  If you find it useful,
please consider joining the user group best for you --
https://tug.org/usergroups.html has a list.  If you're already a member,
thanks very much, your support makes it possible.

Happy TeXing!