Yeah, it can definitely be either. You can either have a website where your homepage is your blog roll (I tend to prefer this approach if your site is active), or you can have a static homepage which may be more of the approach if you have an "exact match domain" or if you have a website that is going to be far more static in nature.

It's often theme dependent. Firstly, go to Settings > Reading and you should be able to decide there if you want your Home page to be a specific page or a blogroll of your latest posts. You should also click on Appearance > Theme > Options and see what facilities the developer of your theme has provided. Rich.