One of the things that really used to bug me was if I was out and needed to connect my MacBook Pro or iPad to my iPhone so I could go the internet. I know wifi is in a lot of place but there are times I need it to connect through my iPhone. I had to switch on my Personal Hotspot and if someone was looking they could see my password. But most annoyingly is it could take ages to connect. That has now been fixed with Instant Hotspot. As long as you are using the same iCloud account on the devices it will connect to your iPhone or iPad if it has a mobile account and you don’t have to worry about passwords. It seems to connect up quickly too. Bluetooth needs to be on and you have to be near you device for it to work. The same applies to Handoff.
Handoff, also known as continuity, allows you to be doing something on your iPhone and for it to pop up in the same place on your iPad or Mac (MacBook, MacBook Pro, MacBook Air, Mac Pro). So if you are looking at something on Safari or any one of a number of other apps including Mail, Maps, Notes, Reminders, Keynote, Contacts, Calendars, Pages, Number or Keynote, then it will automatically pop up on your lock screen on the iPad or in the dock on your Mac. This also works from your iPad to your Mac.
You do need the latest software for the iOS device and also Yosemite on your Mac. It is also dependent on how old your device or computer is.
The easiest way to demonstrate this is to watch the video below.