Webhosting with Apache

As a school project for the second semester we have to program a website and then upload it to a web server that the teacher then can see it. The programming isn't any big problem any more, but I don't know very much about web servers. After some research I found out that the web server Apache is free, but there are still some things not completely clear for me. Does this mean that I don't have to pay any money to host a website with Apache? I heard that there are web servers which have to be rent for a specific amount of time. Why wouldn't everyone just use Apache or other free web servers instead? Thanks in advance for answering my questions.