Hreflang is an HTML attribute that tells search engines which language or regional version of a page to show to which users.
It is used when the same content exists for different languages or countries, for example en-US and en-CA pages with different prices.
Each version should list all the others and itself; one-way or missing references are a common error.
SEO is the work of improving a website so it appears higher in unpaid search results for the searches its customers make.
SEOTechnical SEO makes sure search engines can find, crawl, render and index a website’s pages without problems.
SEOOn-page SEO is optimising the content and HTML of individual pages so they match what searchers are looking for.
SEOOff-page SEO is everything done outside your own website to build its authority, mainly earning links and brand mentions.
