Can someone explain on page seo optimization?

the stuff you change on the page itself to help it rank: title tag, h1 and subheadings, content that actually answers what people searched, internal links to and from it, image alt text, the URL. off page is everything elsewhere, mainly links from other sites. the part people skip is checking intent first. you can tick every on-page box and still not rank if google wants a list of options and you wrote a single product page.