Redis and Mongodb are considered to solve a common problem that “There is something wrong with RDBMS”
So what is difference ?
- Redis is stored in memory and swapped with disk, So data is not lost and you can enjoy performance of your RAM. (Not to be confused with Memcached it is memory only database) whereas Mongodb is disk only database.
- Redis can store many type of object strings, hashes, lists, sets, sorted sets whereas Mongo can only store key value pair in form of document (mongo is schemaless).
- Redis is hard to learn whereas mongo is easier to understand and get started.
- Redis has no support for clustering (Clustering support has been added since version 3.0) whereas mongo has inbuilt clustering support.