MongoDB is a document-oriented database, which means that documents are the basic unit of data storage.

• Documents are JSON objects, which means that they can be easily created and manipulated using JavaScript.
• MongoDB is a schema-less database, which means that you do not need to define a schema for your data.
• This makes MongoDB very flexible and easy to use.

Here's a MongoDB cheatsheet with some commonly used commands and operations:

Database Operations:

• Show all databases: show dbs
• Create or switch to a database: use
• Drop/delete a database: db.dropDatabase()

Collection Operations:

• Show all collections: show collections
• Create a collection: db.createCollection("")
• Drop/delete a collection: db..drop()

Document Operations:

• Insert a document: db..insertOne() or db..insertMany([, , ...])
• Find documents: db..find()
• Update a document: db..updateOne(, ) or db..updateMany(, )
• Delete a document: db..deleteOne() or db..deleteMany()

Query Operators:

• Comparison operators: $eq, $ne, $gt, $gte, $lt, $lte
• Logical operators: $and, $or, $not, $nor
• Element operators: $exists, $type
• Array operators: $in, $nin, $all, $size, $elemMatch

Aggregation Framework:

• Perform aggregation pipeline: db..aggregate([, , ...])
• Common stages: $match, $group, $project, $sort, $limit, $skip, $unwind, $lookup, $addFields

Indexing:

• Create an index: db..createIndex({ "": })
• List all indexes: db..getIndexes()
• Drop an index: db..dropIndex("")

Miscellaneous:

• Count documents: db..countDocuments()
• Show the first document: db..findOne()
• Show the list of databases: show dbs
• Show the current database: db

Please note that represents the name of the collection, represents the query or filter expression, and represents a JSON-like document.