The AND operator in MongoDB is used to filter the data that meets the conditions of multiple expressions. The `$and` operator works in an implicit or explicit way.
```
db.collection.find({ field1: value1, field2: value2 })
```
This will return the documents where `field1` is equal to `value1` AND `field2` is equal to `value2`.
```
db.collection.find({
$and: [
{ field1: value1 },
{ field2: value2 }
]
})
```
This will return the documents where `field1` is equal to `value1` AND `field2` is equal to `value2`.
You can also use the `$and` operator for more complex expressions, like:
```
db.collection.find({
$and: [
{ field1: { $gt: value1 } },
{ field1: { $lt: value2 } }
]
})
```
This will return the documents where `field1` is greater than `value1` AND less than `value2`.
