I stated: "TeXLive is one of several TeX distributions". So why do you ask, "Isn't Texlive a TeX distribution?" (Aside: there are several TeX distributions; TeXLive is just one of them.) The reason I asked if you knew what a TeX di [s]tribution was is that much of your query would appear to pertain to TeX distributions in general, not just TeXLive.
texlive - An error with tlmgr update --all with TL2026? - TeX - LaTeX ...
Seems you have installed two texlive: vanilla texlive + ubuntu texlive packages. And it seems, the vanilla texlive is in the user's PATH, but the ubuntu texlive in root's PATH.
texlive - Local TeX Live is older than remote repository - TeX - LaTeX ...
I recently tried to introduce some fellow students to Latex. I myself used it on linux (ubuntu), and texlive installation trough apt takes about ~2 minutes. As it turns out installation of TeXlive ...
It merely depends on texlive-latex-base, texlive-latex-recommended, and texlive-fonts-recommended. In other words, apt-get install texlive would be a convenient way to install a trimmed down TeX Live distribution with all the recommended CTAN packages.
TexLive allows you to customise what gets installed right at the install time. There are pre-built themes (minimal, basic, medium, full) which is a lot more choice than the base scheme offered by miktex.
texlive - What are the advantages of TeX Live over MiKTeX? - TeX ...
TeX Live from the Terminal/Command Prompt (Windows/Mac/Linux) Understanding the TeX Live update scheme If you have a TeXLive distribution (including MacTeX) there are a few things to understand about updating your system. All TeX distributions consist of both binaries (including scripts) and packages (including classes). It is important to understand that for TeX Live these two parts of the ...