Sometimes you may discover code in your website source that is encoded, this may be due to the developer trying to hide code that is either malicious or protected (such as copy protection etc). However sometimes this code can appear in websites after they have been hacked and the code is used to place malicious content onto your website.
Thankfully base64 is a two way encryption algorithm that allows both encryption and decryption. This is why base64 is not recommended for storing sensitive information such as passwords as anyone with the skills and know how can quite easily decode the data.
Below is such a tool which may be useful for developers or worried business owners, you can create your own base64 content or decode a base64 string.