Since it's not mentioned anywhere in. If you look at rfc 3986 appendix a, you will see that space is simply not mentioned anywhere in the grammar for defining a url. A bit of explaining as to what that %2520 is :
What is the difference and why should this happen? As the aforementioned rfc does not include any reference of encoding spaces as +, i guess using %20 is the way to go today. The common space character is encoded as %20 as you noted yourself.
@metabyter i think it is more technically correct to phrase the question as in a url, should i encode the spaces using %20 or + in the query part of a url? because while the example. I am interested in knowing why '%20' is used as a space in urls, particularly why %20 was used and why we even need it in the first place. The % character is encoded as %25.