It's called a query string ....
Just a web convention thingy.
After the ? is the query string. Groups are separated by the & generally.
youtube.com ? videoNumber=12345 & placeToJumpTo = 2345 & FoundFrom=Search12345
Interwebz no like spaces in names so its substitutes for the equivalent character."%20" = space.
So, you can remove some of the groupings and it would get you where you were going.
Of course, with the web controllers now they don't need the query strings. Though is some cases they do work.
And, of course, while it should be www.com.spacegamer .... it did not look right. So, it became as you know it.
Dumb design but it was practically the computer stone age.