We often hear the words spider crawl when we talk about search engines visiting our websites. Spiders periodically crawl your website at frequent intervals to index your website pages. They look at titles, Meta tags, and the keywords in them, and then follow your keywords throughout your website page. If you have no title or Meta tags, your site will not get index and the spiders will leave your website.
After reading your title and Meta tag, they proceed to the content, searching for your keywords or bolded areas. If your content does not match your keywords, they will move on, not index, and find the site spammy. They should be able to follow clear links to your other pages and continue crawling and looking for your keywords. When you add these links, it shows spiders that you have multiple pages of content on the subject. Making sure to have the links and keywords in the footer will encourage spiders to continue to the next page.
You want your website to be crawled by spiders from search engines. When spiders index your pages, this will allow your website to be reached by more users. When users search using your keywords, your website will appear higher on the list. This will increase traffic and page rank positioning of your website.