Base64 is not for encryption purposes and is not secure. It is an encoding mechanism only.
Encodes a string so that it conforms to the Base64 Data Encodings specification (RFC 4648).
Base64 encoded data is a string of character that contains only a-z, A-Z, 0-9, + and / characters and is often used in situations when sending non-text information via a text only transmission protocol. The string contains text-printable characters.
The = character is a padding character added at the end of the encoding in case the input data is not dividable by 3. If the last 24 bits contain only one character, that character is encoded into two characters and the last two spots will be padded with the characters ==. If the last group contains two characters the encoding will have just one = character.
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/to give us 11 decimal numbers
When you have some binary data that you want to transfer across a network, you generally do not stream the bits and bytes over the wire in a raw format. In addition, some protocols may interpret your binary data as control characters will lead to corrupted data.
To get around this, people encode the binary data into characters. Base 64 is one of these types of encodings.
Base 64 encoding is a way of taking binary data and turning data into text so that it's more easily transmitted in things like e-mail and HTML form data.
The only downside is that base64 encoding will require around 33% more space than regular strings.