Explaining BSON with Examples

Yes. They can contain null values.

BSON has various data types which are not included in JSON, such as Date for datetime and ObjectID.

BSON is a bin­ary-en­coded seri­al­iz­ed format of JSON documents. It provides type and length information in characters that are not human-readable but make it easier for machines to parse.

{"hello": "world"} →

\x16\x00\x00\x00                       // total document size

\x02                                            // 0x02 = type String

hello\x00                                   // field name

\x06\x00\x00\x00world\x00 // field value

\x00                                               // 0x00 = type EOO ('end of object')

BSON is easier to generate and parse for machines and also supports more data types than JSON.