There is nothing called incremental backup in sql server.

There are 3 types of backup

1)Full

2)Differential

c)Transaction Log

Syntax:Full

Backup database database_name to disk='Physical location' with stats=10

Syntax:Differential

Backup database database_name to disk='Physical location' with stats=10 with differential

Syntax:Transaction log

Backup Log database_name to disk='physical location' with stats=10