On-Page SEO is an English term that we use to refer to the optimizations you can make on your page (“On-Page” = On Page), to improve your organic positioning.
That is, everything that depends directly on you, since you are the one who controls your website.
The purpose of On-Page SEO is to “make life easier for Google”, so it can index your pages as quickly as possible… and rank them according to your interest.
To understand, we could say that using On-Page SEO, you will try to “politely explain” to Google what the purpose of your page is.
And please note that I say “politely”, if you go too far Google will stop being your friend, because they will consider you dedicated to “spaming” people and bringing nothing of value.
First, don't take everything you read for granted, not even if you read it here. Only believe what you have personally experienced and it works specifically for your site.
It is true that links, for example, are very important to position competitive terms, but their effectiveness will be much greater if your On-Page SEO is well done.
You can even position yourself for less competitive terms just with good On-Page SEO. In addition, it is quite common for your site to not position itself without a minimum of this work.
It is certain that Google will rank your pages, like it or not, so what do you need to be able to respond to the needs (demand) of users?
Although you won't always convince him to accept your “nominations”, if you omit them or do it incorrectly, you may end up qualifying (ranking) in some surveys that are not what you want.
In other words, it matters a lot that Google finds your pages, and that it understands that you are offering something useful to those looking for solutions on pages like yours.
This is all you can do with On-Page SEO.
For your page to appear in Google results, robots must find it and understand what your intention is.
These “robots” (or “bots”) are computer programs that read, extract and archive the content of pages.
Its mission is to go through the Internet, following all the links it can find, with the aim of locating new pages, and re-visiting those that are already indexed, analyzing whether they have new content.
When a bot arrives on your page, it indexes all the content (text, images, links, code, etc.) and stores it in a gigantic database.
Later, this information will be analyzed to determine the niche your site belongs to, and the relevance it has within it.
However, if the crawling bots can't find your page, or can't index it, it won't show up on Google.
So you should do everything possible to make these bots find and understand your page as easily and efficiently as possible. That's why On-Page SEO is so important, it helps robots at all these points.