Meta tags are snippets of text that describe a webpage's content. They are not visible on the page itself but are included in the HTML code. Search engines like Google use these tags to understand what the page is about, which can influence how the page appears in search results. Common types of meta tags include the title tag, which specifies the title of the webpage, and the meta description tag, which provides a brief summary. Properly using meta tags can improve a website's visibility and click-through rate, making them an essential part of SEO (Search Engine Optimization).