With Handoff, you can start work on one device, then switch to another nearby device and pick up where you left off. Before beginning, make sure every device you want Handoff used on are signed-in with the same Apple ID and iCloud account. Also make sure each device has Bluetooth and Wi-Fi enabled.
Turn on Handoff
On Mac, click the Apple menu
Click System Preferences
Select Allow Handoff between this Mac and your iCloud devices
Turn on Handoff on iPhone or iPad by going to Settings > General > AirPlay & Handoff >then turn on Handoff
With Apple Watch, go to the Apple Watch app on your iPhone, tap General > turn on Enable Handoff