Base64 encoding and URL encoding

What is Base64 encoding? Where is it used?

1) Base64 is a generic term for any number of similar encoding schemes that encodes binary data by treating it numerically and translating it into a base 64 representation.
2) The Base64 term originates from a specific MIME content transfer encoding.
3) Base64 encoding schemes are commonly used when there is a need to encode binary data that needs be stored and transferred over media that are designed to deal with textual data.
4) This is to ensure that the data remains intact without modification during transport.
5) Base64 is used commonly in a number of applications including email via MIME, and storing complex data in xml.
What is URL encoding? Where is it used?

1) URL Encoding is the process of converting string into valid URL format.
2) Valid URL format means that the URL contains only what is termed "alpha | digit | safe | extra | escape" characters.
3) URL encoding is normally performed to convert data passed via html forms, because such data may contain special character, such as "/", ".", "#", and so on, which could either:
a) Have special meanings; or
b) Is not a valid character for an URL; or
c) Could be altered during transfer.

4) One of the most common encounters with URL Encoding is when dealing with s.

5) URL encoding converts characters into a format that can be safely transmitted over the Internet.
6) URL encoding replaces unsafe ASCII characters with "%" followed by two hexadecimal digits corresponding to the character values in the ISO-8859-1 character-set.