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    What is SEO, explained with diagrams

    How Google finds, stores and orders pages — and what a backlink really is. Six diagrams, one for each piece.

    2026-10-14·7 min read·SEO·POSTEP Digital

    Google reads a catalogue, not the internet · SEO = content + technical + authority · a backlink is a recommendation, not a purchase · ads are a tap, SEO is a well

    // 01

    Start here: Google doesn't search the internet

    When you search, Google doesn't go looking across the internet. It checks a copy it stored beforehand — like a library where someone read and catalogued every book long before you reached the desk.

    diagram 01
    How a page travels to your screen
    Out there
    The web
    billions of pages, no order at all
    a robot hops from link to link
    Step 1 · Crawl
    Googlebot
    visits the page and reads what's on it
    copies it and sends it home
    Step 2 · Index
    Google's index
    the giant library of organized copies
    someone types a search
    Step 3 · Rank
    Order the candidates
    thousands of pages compete, 10 show up
    in under a second
    Step 4 · Serve
    The results page
    what you see when you search
    Look at step 1: the robot reaches you by following links from other sites. A site nobody points to takes far longer to be found — that's why backlinks aren't a detail.
    A page that never enters the index simply doesn't exist for search. It isn't "ranking poorly": it isn't in the game at all.
    Diagram 1: the web full of pages, Googlebot crawling link by link, the index storing copies and the search returning the result on screen.

    → Hold on to step 1. It's where the answer to “why do backlinks matter so much?” comes from, further down.

    // 02

    What you're actually looking at when you search

    The screen stacks two blocks, alike on purpose. Up top, the ads: whoever sits there paid. Below, the organic results: whoever sits there was picked by Google as the best answer. SEO is the work of occupying the second block — it stands for Search Engine Optimization.

    diagram 02
    What's paid and what's earned on the results screen
    pool repair in curitiba
    Sponsored
    Pool Express — Quote in 2 hours
    poolexpress.com/quote
    Pool Renovation | Serving Curitiba
    poolrenovation.com
    ad · you pay per click
    Google results
    1
    Pool repair: when it can be patched and when it must be replaced
    coberpool.com › blog › repair
    2
    Vinyl pool leaks — the 2026 guide
    coberpool.com › guides › leaks
    3
    How much pool repair costs in Curitiba
    southpools.com › pricing
    organic · the click is not charged
    Both blocks fight for the same screen. The difference is the price of a click: up top you pay every single time; down below you paid once to build the page and it keeps bringing people in.
    Attention collapses with every position down. Being on page 2 is, in practice, not being there.
    Diagram 2: a Google results page split into two blocks, paid ads on top and organic results below.

    → The organic click isn't “free”: you pay by building the page. The difference is you pay once, not per visit.

    // 03

    So what is SEO, exactly?

    It isn't a trick, and it isn't a magic word repeated twenty times in the text. It's three questions Google asks about your site — three fronts that move together.

    diagram 03
    SEO in three questions Google asks about your site
    pillar 1
    Content
    “does this answer what the person asked?”
    one page per real question, not one generic page for everything
    written for readers, not to please a robot
    more complete than whatever ranks first today
    pillar 2
    Technical
    “can this site be entered, read and used?”
    loads fast, including on mobile data
    actually works on a phone
    the robot can crawl and index the pages
    pillar 3
    Authority
    “do other people trust this site?”
    other sites mention and link to yours
    the brand shows up where the topic is discussed
    this is where backlinks come in
    all three together = position
    It isn't a menu where you pick one. Miss one and the other two won't cover for it: great content on a site that won't load doesn't rank, and a flawless site with no content has nothing to rank.
    Diagram 3: the three pillars of SEO, content that answers, a technically healthy site and authority coming from external links.

    Two pillars depend only on you: writing well and keeping the site healthy. The third depends on other people — and it's the hardest one to fake.

    // 05

    How Google decides who comes first

    Nobody outside knows the exact recipe, and it changes constantly. But the spirit is public and fits into four questions, answered all at once in under a second.

    diagram 05
    The questions that decide who comes first
    Goes in
    A person's search
    “pool repair in curitiba”
    Google weighs it all at once
    Four filters
    1Intent
    what do they actually want?
    buying, learning or finding an address change the whole result
    2Relevance
    does this page answer that?
    the page topic matches the search
    3Authority
    can we trust who wrote it?
    this is where backlinks and site history come in
    4Experience
    is this page good to use?
    speed, mobile, no pop-up covering the text
    a combined score, not a single scoreboard
    Comes out
    The order of page one
    recalculated on every search
    where you are
    on which device
    at what moment
    That's why “being number 1 on Google” doesn't exist. Being first for that search, in that city, in that context does — and your results screen isn't the same as your neighbour's.
    Diagram 5: the four questions Google answers when ordering results, intent, trust, speed and experience.

    The first is the most ignored. “Pool” can be someone wanting to build one, repair theirs, or just learn the ideal water temperature: three different results for the same word.

    // 06

    SEO or ads? The tap and the well

    Every first meeting has this question. The honest answer is that the two solve different problems: ads are a tap, SEO is a well.

    diagram 06
    The tap and the well
    ads
    The tap
    Open it and water comes instantly. Close it and it stops the same day.
    shows up today, in the top spot
    you pay for every click, always
    stop paying and traffic stops
    12345
    traffic per month · the last bar is the month the budget stopped
    SEO
    The well
    You dig for weeks seeing no water. Then it comes on its own, every day.
    takes weeks or months to show up
    the click isn't charged
    keeps bringing people in once it's built
    12345
    traffic per month · same scale as the other side
    It isn't either/or. Ads buy time — you need customers this month. SEO buys permanence — you don't want to start from zero every month. The healthy way is running both: ads fund the present while SEO builds the future.
    Diagram 6: ads compared to SEO, the tap that stops when you close it and the well that keeps giving water.

    → Open only the tap and you're hostage to it. Dig only the well and you starve halfway through.

    // 07

    Where to start, in order

    The order that works — not the most exciting one, the one that doesn't waste effort.

    1

    Open your site on a phone, on mobile data, with a stopwatch. If it drags, nothing else matters.

    2

    Write down what your customers ask before buying. Every question is a page.

    3

    Answer one question per page, better than whoever ranks first today. One page, done well.

    4

    Cover the technical basics: a unique title per page, an address that makes sense, and the whole site reachable by links.

    5

    Only then go after links — partners, associations, local press, suppliers who already talk about you.

    6

    Measure with Search Console (it's free) and wait. SEO results show up in months, not days.

    the whole thing in one line

    SEO is being the best answer to a question someone typed, on a site that loads fast, with people outside vouching that you're trustworthy. The rest is execution detail.

    // 08

    Frequently asked questions about SEO

    What is SEO, in one sentence?

    SEO is the set of adjustments that get a page to show up in Google's unpaid results. Instead of paying per click, you pay once, by building the page.

    How long does SEO take to work?

    Months, not days. Technical fixes show up in weeks; a new page usually takes three to six months to hold a position; authority is the slowest part, because it depends on other sites.

    What is a backlink and how do you get one?

    It is a link from another site pointing at yours, which Google reads as a vote of confidence. The ones that count come from partners, associations, local press and suppliers who already talk about you. A bought package will not lift your position and can sink it.

    SEO or Google Ads: which one?

    Ads bring visits today and stop the day you switch them off. SEO is slow and keeps going. If you can do both, use ads to find out which searches convert and SEO so you do not depend on them.

    written by
    POSTEP Digital
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