If you have a password set on your computer, then the first screen you will see is the lock screen

 

This screen shows a chosen background picture (or slideshow of your pictures) along with the date/time, status of your internet/network connection, battery level (if using a laptop/tablet) and can also include other notifications such as calendar alerts, emails, skype calls (which you can answer from the lock screen) and alarms - all these options can be configured in the Lock Screen section of PC Settings

 

To access your computer click anywhere on the screen, press the spacebar, or swipe upwards if using a tablet and you will then be presented with the log-in screen, where you can enter your password

 

If you have a device with a camera then you can swipe downwards on the lock screen to use it without having to log-in first

 

This screen also contains buttons for Ease of Access options and to Shut down or Restart your computer