A web host is a service that stores your information (or website) on a server, allowing it to be accessed by users on the Internet. Web hosts typically charge by the month, with discounts if you pay by the year. For most simple sites hosting charges should be minimal, around $5-$10/month. Web hosts often double as registrars, and offer hosting packages which come with one or more free domain names. I have happily used 1and1.com for many years and can recommend them - their prices are low and they offer a lot of features.
If you sign up for a free blog at Wordpress.com or Blogger.com you don’t need a separate web host because they host the blog for you. The advantage is an extremely easy-to-use CMS interface and pre-made, professional designs. The disadvantages include not having your own domain name and some limitations in terms of functionality, storage space and design.