The 7 differences between SEO & SEM

Posted 4 August 2021 Agence Rinaldi in Our experts

Marketing is constantly evolving! And, let’s face it, the vocabulary around digital marketing is a flourishing one that involves hundreds of new acronyms.

Today, we’re brushing up on our classics and focusing on two relatively common acronyms that are often confused for one another: SEO and SEM.

As a reminder, SEO is a method used to improve the ranking of a website within search results. We’re talking content and technical optimization to match that of search engine algorithms.

SEM, on the other hand, is a method that covers paid advertising on search engines. Its role is to generate qualified traffic.

SEO and SEM have a complementary relationship, and when both are exploited to their fullest potential, they can bring you great business results.

To help you see more clearly and avoid any mistake, our team has prepared a chart highlighting the seven differences between these two methods!



– SEO: search engine optimization

Algorithm: set of operations performed by search engines to rank information by relevance.

– Netlinking: set of actions aimed at creating inbound links (backlinks) on a site to increase its popularity.

– Title tag: the HTML <title> tag designates the page title that appears in search engine results pages (SERP).


-SEM: search engine marketing

– Acquisition tunnel: route followed by an Internet user from his arrival on the site to the order confirmation; it’s also called the purchasing journey.

– CTR: criteria for evaluating an online advertising campaign – number of clicks on a given ad divided by the total number of views.

– A / B testing: method allowing the comparison of different versions of the same object in order to optimize conversion rates.


SEO: To increase the positioning of your website and appear at the top of search engine results.

SEM: To generate qualified traffic: Make ads appear at the top of search engine results, with the right audience at the right time in the acquisition journey.



– Analyzing your website like a search engine robot.

– Choosing the right performing keywords for your website.

– Improving the content of the website.

– Improving the speed of the website.

– Reviewing the construction of the site and the internal mesh.


– Analyzing your personas, their sales journey and the associated keywords.

– Defining your objectives and an acquisition strategy.

– Building ads in accordance with the brand image, keywords, targeting, landing page, acquisition strategy and Google algorithms.

– Testing audiences, ads, keywords and analyzing the results.



– Media: No charge

– Time + resources + expertise


– Media: Paid

– Time + resources + expertise


SEO: Long term: between 6 months and 2 years

SEM: Instant, as soon as the campaign starts!

When to use it? 


SEO is necessary as soon as your website goes live.

– This leverage is essential for your business, because it is the one that allows you to be visible in the long term.


– Complementary to SEO, SEM allows an immediate presence on search engines.

– Necessary for all commercial operations, such as the development of a new product / service or a commercial action to reach a new target.

– Useful to stand out from the competition.


Useful platforms


– Website.

– SEM Rush.

– Screaming Frog.

– Ahrefs.

– Google Search Console.

-Google Keyword Planner.


– Google Analytics.

– Google Keyword Planner.

– Google My Business.

– Google Ads.

– Website.

– Supermetrics.


Blandine ChateauDigital campaign strategist