Visits represent the number of times a website is accessed by users. Visits are always trying to be increased in order to drive sales so advertising is used to link the site to potential areas of interest to a mutual target market.
Most analytical tools report unique visits if they are made using the same device and the same browser. However, if the visitor has disabled the cookies, then the visits will not be recorded as returning visitor. While number of visits is an important indicator of the website performance, it is by no means a crucial one.
Visits alone will not make money for the website, but conversions. It is the task of conversion optimization to make the most of the existing visitors, rather than to attract more new visits.