Home insurance or house insurance (don't worry they're the same) encapsulates two main types of policy. In your home insurance policy you can have both policies or just one of the two. You can tailor your policy exactly to your needs.
Buildings insurance - Covering the structure (bricks and mortar) of the home. The easiest way to think about this is to imagine what would happen if you could lift your property up, turn it upside down and shake it. All the things that would fall off will be treated as contents, everything else will come under the buildings insurance policy.
Contents insurance - Covering the contents of the home and possibly some element of personal possessions (such as jewellery) which are removed from the home.
You can buy contents and buildings individually or as one combined policy. It is often better to buy a single combined policy because in the event of making a claim you will only have to deal with a single insurer. This can be particularly important with water damage claims which will often affect both the building and the contents.