sometimes a website might have a page with a list of links, why is that and whats the significance?

Hi,
Generally a "Links" page is designed to increase peoples' awareness of their website or increase the number of products they may wish to sell in the marketplace.
Most websites with similar interests such as family history groups, community societies, etc, will usually show 'links' to other websites in order to expand everyones knowledge about that particular subject. Everyone benefits!

well, It is obviously the link that are up on the site trying to convince you to visit it. I don't know it could be another site for you to check out or similar websites. It might be commercials. It is a choice. I'm not sure if that what you were trying to ask. But i think that's what for.

An example would be helpful, but I assume that you are referring to directory listing pages. This simply means that the web server was unable to find a default page for that directory (usually a file named index.html) and instead just lists the contents of that directory. Sometimes the web server is configured to not do this, though the default is usually to perform directory listing.

Only thing I could think of is that they are advertisements

I think you're referring to spoof sites that have their name similar to other familiar names (e.g. www.zonalarm.com instead of www.zonealarm.com)
which are potentially malicious.

Are you referring to the sitemap? If yes, the sitemap is used as a directory of the pages of a website (think the directory map at the mall) and it is also used to increase the site's visibility in search engine results. A sitemap make is easier for search engines, such as Google, to crawl and index the website.

http://www.sitemaps.org/

A list of links is like a table of contents in the front of a book, or an index in the back of a book, it provides you with a way to find information that is not included within the page, and might be elsewhere on the website, or located on computers elsewhere on the Internet.