Today, however, SEM is used to refer exclusively to paid search. According to Search Engine Land, Search Engine Marketing is “the process of gaining website traffic by purchasing ads on search engines.” Search Engine Optimization, on the other hand, is defined as “the process of getting traffic from free, organic, editorial or natural search results.”

Alt text (alternative text), also known as "alt attributes" describe the appearance and function of an image on a page. Alt text uses: 1. Adding alternative text to photos is first and foremost a principle of web accessibility. Visually impaired users using screen readers will be read an alt attribute to better understand an on-page image. 2. Alt tags will be displayed in place of an image if an image file cannot be loaded. 3. Alt tags provide better image context/descriptions to search engine crawlers, helping them to index an image properly.
To get even more insight and data to help you make those decisions, sign up for a free trial of Alexa’s Advanced Plan. You’ll get access to tools that help you research competitor search and link building strategies, find keyword opportunities, review your site’s SEO, and learn about your target audience. These insights, paired with what you know about SEM and SEO, will help you uncover the best search marketing strategy for your unique brand and goals.
However, that’s totally impractical for established sites with hundreds of pages, so you’ll need a tool to do it for you. For example, with SEMRush, you can type your domain into the search box, wait for the report to run, and see the top organic keywords you are ranking for. Or, use their keyword position tracking tool to track the exact keywords you’re trying to rank for.

SEM search placements include an “Ad” designation. SEO does not. Search results that appear as a result of SEM or SEO look different on SERPs. Paid ads that receive placement through SEM tactics are often identified as an ad (e.g., by an icon appearing next to the placement), whereas the search results that appear as a result of organic SEO are not marked in such manner.
Both use keyword research to uncover popular search terms. The first step for both SEM and SEO is performing keyword research to identify the best keywords to target. The research includes looking at keyword popularity to determine the top keywords or buying keywords that your ideal audience searches for. It also includes looking at keyword competition to see what other brands are targeting the same keywords and determining what you will need to do to compete with those other companies.
The leading search engines, such as Google, Bing and Yahoo!, use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. The Yahoo! Directory and DMOZ, two major directories which closed in 2014 and 2017 respectively, both required manual submission and human editorial review.[40] Google offers Google Search Console, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that are not discoverable by automatically following links[41] in addition to their URL submission console.[42] Yahoo! formerly operated a paid submission service that guaranteed crawling for a cost per click;[43] however, this practice was discontinued in 2009.

Optimizing a website may involve editing its content, adding content, and modifying HTML and associated coding to both increase its relevance to specific keywords and remove barriers to the indexing activities of search engines like Google ,Yahoo etc.[citation needed] Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.[3]