What does service coverage mean, is this different from AppleCare?

It's not. That just means how many days your computer is covered under it's present warranty.

Mort

Are you sure you don't already have it? The number of days left is well over a year so it indicates you already bought it. Mine has a 174 days left on it's first year warranty. I have to purchase applecare before the end of the first year to extend it with applecare. Check your receipt.

Mort

... usually (from my own experience) this means that your computer is covered under one of the special "PLA" (parts & labour agreement) that Apple offers to EDU and business customers. These are 3 year extended warranties, but unlike the full fledged AppleCare only cover the computer and not any peripherals. AppleCare would, e.g., also cover an AirPort base station.

AppleCare service agreement is on this page:
http://www.apple.com/support/products/