This article explains how to set up screen sharing on a Mac using the Screen Sharing preference pane.
How to Share Screen from Macbook Pro to iMac 5K – Screen Sharing on Mac OS
The Mac offers two ways to set up screen sharing: one is aptly called Screen Sharing and the other is called Remote Management. This article assumes that you will be using the basic Screen Sharing, which is more applicable to most home and small business users.
Launch System Preferences by clicking the System Preferences icon in the Dock or by selecting System Preferences from the Apple menu.
Click the Sharing preference pane in the System Preferences window.