crawl on the web pages. No matter what kind of content is - it can be videos, PDFs, images or any other format it doesn't affect the crawl ability. How this process works - If a person is asking a question on a search engine, then your answer should be compelling so user clicks on your website for more information. Good use of keywords can increase the rate of visitors on your website. These things matters a lot - Why? Because these things make your content visible without this your content will never find out. Although, it doesn't matter that how healthy or good your content is, if it's not visible to audiences.