Sometimes you have a tiny file you wish to include in a block of plain text, perhaps an email. When I was young(er), -in the era of UUCP and modems, before the world wide web and HTML were invented, when RFC-821 was still new, -there were no MIME attachments to email.
If you wanted to send a file by mail, you had to encode it in a way that could be included in plain text without breaking. That meant 7-bit ASCII only, max 72 chars on each line, and a lot of other limitations.
Bandwidth and storage were limited, so uuencode was invented to “efficiently” encode 3 bytes of binary data into 4 printable characters. Pretty clever.
I recently had a need for uuencode, and it was not installed on my CentOS/RedHat system by default. The package containing uuencode is called “sharutils”. The name comes from the “shar” utility to encode binaries into a shell script, shell archive (shar file).
“yum install sharutils” – and voila, I have uuencode and uudecode available.