Headers in various sizes are one of the most important elements of the visual aspect of the site, which is also important for search engines. The letter “H” is an abbreviation for the word “Heading”, which is followed by a number referring to its size, but arranged in the opposite way. Namely, the number 1 symbolizes the most important heading, and the lower the number – the less significant the heading is. With their help, we can direct the reader as to the structure of a given subpage and show the search engine which of the phrases is the most important and which accurately describes the text on this subpage. Proper use of headlines is therefore a very key element for the operation of search engines, and very helpful for readers of a given website.