I have this "internal server error" on my landing page! What is it?

I'm doing a landing page and I put it into a subdomain.

I receive this error on my awstats.

HTTP Error codes
HTTP Error codes* Hits Percent Bandwidth
500 Internal server Error 574 98.4 % 498.33 KB
206 Partial Content 9 1.5 % 157.84 KB

what's the meaning of this error? and looks like I have 574 hits. That is too many right?
Is this something bad? How can I rectify this? Thanks a lot guys.