On a country basis or on a global platform does the SEO on a website function?

Is it true that SEO operates on the basis of a single market or simultaneously are the other markets also captured? What would the best approach be to make it a multi-market system if mostly the SEO works on a single market basis? This problem has been bothering me for quite sometime now as I want my websites to appeal on a global level and not only on a local level. I want these websites to have a really widespread reach. Does anyone have any recommendation?

Well, SEO work globally but there is also a local search engine optimization, which is called Local SEO. In local SEO , maps and physical address matters a lot. You can get plenty of tutorial about local SEO . just google it