Meta tags are lines in a page's code that describe it to search engines and to people looking at the results. Two of them matter most. The title is the page's headline, visible in the browser tab and in search results. The description is the short summary Google usually shows under that headline.
Visitors never see these tags on the page itself, which is why they get forgotten. Yet they answer the question "is this worth a click?", and everything that happens afterward depends on that click. Every page needs its own pair. When the tags are missing, the search engine assembles a snippet from whatever fragments of text it finds, and the result is rarely flattering.
Put simply, meta tags are the shop window of each page in search. If the headline is empty, generic or cut off mid-word, people walk past, however good the page behind it is.
Next to them sits the H1, the headline on the page itself. It should match the title in meaning but not word for word. We write the three together so they never contradict each other.