This answer helped me with running Selenium.
now...why is the solution to use wget? How do you know which is the latest version? Why not use git?
You clone it the same way you would clone any Git repo.
git clone https://github.com/mozilla/geckodriver
why is the solution to use wget
wget is installed by default and git isn't.
How do you know which is the latest version?
Look at the releases page.
Why not use git?
See above.