# Basics

MS SQL is a set of windows services that runs on the Windows OS as a service account. 

High level of existing SQL Server account types:

* Windows Accounts.
* SQL Server Logins (Inside SQL Server).
* Database Users(Inside SQL Server).

MS SQL Server common roles are:

* Sysadmin role –> Windows Admin for SQL Server.
* public role –> Least privilege, something like Everyone group in Windows.
* [Full list](https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/server-level-roles?view=sql-server-2017).