The primary backup tool is mongodump, which is run from the command line (not from the mongo shell!). This command is able to back up the local MongoDB database of any accessible host. The output from this command is in the form of Binary Serialized Object Notation (BSON) documents, which are compressed binary equivalents of JSON documents. When backing up, there are a number of options available in the form of command-line switches, which affect what is backed up, and how.
If you want to back up everything in the local MongoDB database, just type mongodump. A directory called dump will be created; each database will have its own subdirectory, and each collection its own backup file.
For documentation on BSON, see http://bsonspec.org/. For documentation on JSON, see http://json.org/.
