2 examples for mongodump
# Export a database named "dbname" from localhost to your home directory (creating a sub-directory with all of the contents)
mongodump -d dbname -o ~/
# Export a remote database named "database-name" from a connection string URI to a local directory...
mongodump --uri mongodb://connection:string@hostname.com:27000/database-name -o ~/MyMongoExports/