Wayback Machine - It enables you to capture, manage and search collections of digital content without any technical expertise or hosting facilities.
The Internet Archive, a 501(c)(3) non-profit, is building a digital library of Internet sites and other cultural artifacts in digital form. Like a paper library, we provide free access to researchers, historians, scholars, people with print disabilities, and the general public. Our mission is to provide Universal Access to All Knowledge.
The Wayback Machine service is necessary to check domains before buying, or possibly in the process of website promotion, for its history of existence, which is very important for its further SEO promotion. For example: if you buy a domain for a lawyer's site, and earlier there was a game portal on this domain, this may adversely affect the promotion of a new site on this domain, so in such cases it is better to refuse the purchase.