The page title is the text defined in a page's HTML title element (<title>...</title>). It appears as the label on the browser tab and, in most cases, as the blue clickable link for that page in search results. Every page should carry its own unique title.
The title sits in the <head> section of the HTML, so visitors never read it in the page body. Instead it surfaces in three places: the browser tab, the search result headline, and the label when someone bookmarks or shares the page. Because it is often the first thing a searcher sees, it strongly influences whether they click.
These get muddled constantly. The page title is the <title> element (browser tab and search link). The H1 is the main heading shown on the page itself. The meta description is the summary snippet beneath the link. They can share wording, but they are separate elements, and "meta title" is simply another name for the page title.
A blog used the same generic title, "Blog | Acme Co.", on every article because of a bad template. Search results showed dozens of identical blue links and click-through was poor. Giving each post a unique, descriptive title (for example, "How to Repot a Fiddle-Leaf Fig | Acme Co.") lifted organic CTR on those pages by roughly 30%. Getting titles right is foundational on-page SEO.