A binary-safe string is one that can consist of any characters (bytes)
Strings in Redis are binary safe, meaning they have a known length not determined by any special terminating characters.
For example, many programming languages use the 0x00 character as an end-of-string marker, so in that sense a binary safe string is one that can consist of these.
Thus, you can store anything up to 512 megabytes in one string.
Redis Strings are binary safe, this means that a Redis string can contain any kind of data, for instance a JPEG image or a serialized Ruby object.
Any object can be serialized to a string
String can behave as a random access vertor too
Large data like a wikipedia page can be encoded into small format and stored as a string
Max Size 512 MB
Use cases
Storing static website pages
Redis.io website uses Redis database itself to serve as a static page