60% of traffic on Google is from mobile.
Mobile SEO is helped by responsive web design. This means images have to be rendered on a website to fit the screen size. There also has to be a focus on improving website access speed, content visibility and easy navigation for mobile users.
SEO (Search Engine Optimization) is  the methodology of strategies, techniques and tactics used to increase the amount of visitors to a website by obtaining a high-ranking placement in the search results page of a search engine (SERP).
Responsive web design is one of the differences between Desktop SEO and Mobile SEO. But there are others. There are also similarities.
Here are 5 similarities and 6 differences between Desktop SEO and Mobile SEO.
SIMILARITIES

1. GOOD AND RICH CONTENT: Whether it’s Desktop of Mobile, good SEO content has to be created with the goal of attracting search engine traffic. But search engine don’t buy your product, people do. To gain the attention of both, well written content created with Keyword Research and Content Organization has to happen.
2. NATURAL BACKLINK PORTFOLIO: Creating good content is the best way to build a natural backlink portfolio. Link building is still one of the most important things you can do in terms of off-site search engine optimization. Link Requests, Content Links and Social Links are practices to incorporate in Content Creation to build links naturally.
3. SOCIAL SIGNALS: What impact do social signals have on our SEO efforts? Social signals let search engines know your site is being talked about. When those social signals (Tweets and Likes) turn into social shares, if your content is good, people will share and might  link to your content.
4. SEMANTIC KEYWORD OPTIMIZATION: Semantic search is technology that tries to determine what users mean when they type in a certain keyword. If you used Google search on your smart phone to find “laptop repair.” Semantic search recognizes your location via your GPS on your phone and delivers you “laptop repair” results based on location. Semantic search takes into account related terms that often people use.
5. CONVERSION OPTIMIZATION: Take a look at your site or pages as though this is the first time you’ve ever seen them. Is the navigation clear? Are the links visible? Conversion Rate Optimization involves an in-depth look at at structure, content and results of your site to make sure you are delivering the best user experience on all devices.

DIFFERENCES

1. RANKING ALGORITHMS: To encourage global compliance, Google has made changes to its mobile SEO rank algorithm to rank websites that follow its recommendations higher than websites that do not. You can check your site by testing your pages with the Mobile-Friendly Test tool. This tool shows how Google Search sees your pages.
2. SCROLLS INSTEAD OF SCANS: Mobile search is condensed because the user scrolls instead of scans from left to right. Knowledge graph cards are in-line on mobile and push results down further. Meta descriptions are truncated at a shorter limit, so keep the most impactful part of your message within the first 100-110 characters.
3. LOCAL LISTING OPTIMIZATION: 53% of mobile searches have local intent. Make sure you have location targeted pages with the targeted location prominent in all relevant places (such as title tags, descriptions, and unique content). Create a profile with Google+ Local (within Google Places for Business). Don’t forget to include images of your storefront in your Google+ Local listing. This will be shown in Google Maps.
4. VOICE SEARCH AS A KEYWORD TOOL: You may or may not use voice search on your phone, but many people already do and more will be. In fact, 55% of teens use voice search more than once per day. People turn to their smartphones in moments when they need something completed — they want to find a hotel, they want to buy a sweater, they want to know how to get to a restaurant. Google refers to these intent-driven moments of decision-making as “Micro Moments.” Voice search increases the relevance of semantic search, mostly because users will be speaking naturally in order to enter a search query. Searches will become more conversational. That means they will be longer keyword phrases and questions.
5. QR CODES: Although some think QR Codes disrupt SEO because they eliminate the need for a search engine, the lightning fast speed you get the info and often at the point of purchase is a difference that helps connect consumer with the information they are searching and the mobile device in their hand and that’s was SEO is all about.
6. LEVELS OF ENGAGEMENT: A mobile searcher (compared to a desktop searcher) is highly engaged, but is less interested in scrolling than a desktop searcher. First position matters even more in mobile. A drop from first to fourth position on mobile phone can mean a Click Through Rate (CTR) drop off of more than 90%.

These similarities and differences show people behave differently when they search on desktop and mobile device, but principles of effective SEO still apply.
Do they teach something new about Desktop SEO and Mobile SEO? Is your business paying attention to both?