||A fixed-sized collection that automatically overwrites its oldest entries when it reaches its maximum size.
||A capped collection that stores an ordered history of logical writes to a MongoDB database. The oplog is the basic mechanism enabling replication in MongoDB.
||(JSON document path) The required sequence of keys to access one specific value of the document (for example, address.zipcode)
||A replica set is the way provided by MongoDB to add redundancy to survive network partitions and other technical failures (more info)
||When the amount of data is too large it is recommended to distribute the information across multiple machines, this is known as sharding in MongoDB (more info)