The output is one block for your page's <head>, containing only the tags you actually filled in. Title and meta description control your search result. Canonical tells search engines which URL is the real one when the same content is reachable at more than one address. Robots controls whether the page may appear in search at all. The Open Graph tags control the preview card on Facebook, LinkedIn, WhatsApp, Slack, and Discord, and the two Twitter Card tags cover what X reads that Open Graph doesn't.
Values are escaped as they're written into the attributes, so quotes and ampersands in your title or description won't break the markup. To check what a page is already serving rather than what you plan to publish, run it through the Meta Tag Analyzer, and use the SERP Snippet Preview for pixel-accurate truncation.