If you haven't read the posts about What is the Digital Marketing? and What are the Search Engines and How do they work? I recommend you go and check them out before you continue reading this post, so you can better understand the content in this post.
The Meta tags, also called tags are a fundamental part of SEO strategies, and as it has been mentioned in previous posts, they are part of the SEO strategies that are not visible to the naked eye when you are in a website, but they are the ones that make the Search Engines work easier by making your content more visible and understandable to them, so when they interact with your pages they can understand the overall structure of your website and can eventually rank better.
Therefore, it is very important to know them and understand how they work; they are nothing more than HTML codes that are inserted in the web pages that express in a clear and short way the main idea of the content or the overall context that surrounds it. It is basically the way in which the SERPs algorithms can understand and quickly identify the content inside your page and its intention so they can index it properly, and eventually present it to a user who is searching about a topic in specific.
More importantly, using the Meta tags properly can help your website to stand out from the rest on the internet when users are searching for content that is related to your website.