Look at SQL Server Fixed Database roles.

SQL Server provides some built-in fixed database roles predefined in the database like db_owner ,db_securityadmin etc.

In order to manage permissions on a database easily, SQL Sever provides following Fixed database roles: 1)db_owner : This role perform all configuration and maintenance activities on the database, and can also drop the database. 2)db_securityadmin : This role can modify role membership and manage permissions. Adding principals to this role could enable unintended privilege escalation. 3)db_accessadmin : This role can add or remove access to the database for Windows logins, Windows groups, and SQL Server logins. 4)db_backupoperator : This role can back up the database. 5)db_ddladmin : This role can run any DDL command on a database. 6)db_datawriter : This role can add, delete, or change data in all user tables. 7) db_datareader : This role can read all data from all user tables.