Mapping network drives is essential to the way that most companies do business. Data is power, data is currency. All organizations create and own new data every day, and they all need a place to store that data. You're certainly not going to let users keep the only copies of their documents on local hard drives, so you of course have file servers to store this data. While the landscape of file storage is ever-changing, especially lately with the move to hyper-converged infrastructure, the fact that your users need drives mapped to those file-storage locations hasn't changed. There are multiple ways that drive mappings could be handled within Windows, including logon scripts that we could run via Group Policy, but let's take a look at a capability that is more natively available inside Group Policy preferences:

User Configuration | Preferences | Windows Settings | Drive Maps

Right-click on Drive Maps, and choose New | Mapped Drive. All you have to do is specify the network location that the drive needs to be mapped to, and then you can select to utilize a statically assigned drive letter on the local machine, or have the computer grab whatever the first available drive letter is. This option allows some flexibility on a per-machine basis if your users have other network drives created and you don't have them standardized.

I am going to map my S: drive to \DC1Sales, a new share that I just finished creating:

After linking this GPO to my user account and logging in to my laptop, I can now open up File Explorer and see the automatically created S: drive mapping to my Sales drive: