Having a different description meta tag for each page helps both users and Google, especially in searches where users may bring up multiple pages on your domain (for example, searches using the site: operator). If your site has thousands or even millions of pages, hand-crafting description meta tags probably isn't feasible. In this case, you could automatically generate description meta tags based on each page's content.
The world is mobile today. Most people are searching on Google using a mobile device. The desktop version of a site might be difficult to view and use on a mobile device. As a result, having a mobile ready site is critical to your online presence. In fact, starting in late 2016, Google has begun experiments to primarily use the mobile version of a site's content42 for ranking, parsing structured data, and generating snippets.
As the number of sites on the Web increased in the mid-to-late 1990s, search engines started appearing to help people find information quickly. Search engines developed business models to finance their services, such as pay per click programs offered by Open Text in 1996 and then Goto.com in 1998. Goto.com later changed its name to Overture in 2001, was purchased by Yahoo! in 2003, and now offers paid search opportunities for advertisers through Yahoo! Search Marketing. Google also began to offer advertisements on search results pages in 2000 through the Google AdWords program. By 2007, pay-per-click programs proved to be primary moneymakers for search engines. In a market dominated by Google, in 2009 Yahoo! and Microsoft announced the intention to forge an alliance. The Yahoo! & Microsoft Search Alliance eventually received approval from regulators in the US and Europe in February 2010.
Off page SEO: This type of SEO focuses on all of the activity that takes place "off the page" when looking to optimize your website. "What activity not on my own website could affect my ranking?" You might ask. The answer is inbound links, also known as backlinks. The number of publishers that link to you, and the relative "authority" of those publishers, affect how highly you rank for the keywords you care about. By networking with other publishers, writing guest posts on these websites (and linking back to your website), and generating external attention, you can earn the backlinks you need to move your website up on all the right SERPs.