Base64 is a group of tetrasexagesimal binary-to-text encoding schemes that represent binary data (more specifically, a sequence of 8-bit bytes) in sequences of 24 bits that can be represented by four 6-bit Base64 digits. (Source :- Wikipedia)
Base64 is designed to carry data across channels. These data are stored in binary formats. Base64 is widely used to send email attachments over the World Wide Web. Base64 can be used in any context where you want to transmit binary data in text format.