SEO (Search Engine Optimization) is needed for your website if you want to rank on the SERP . The one you should really be shooting for is Google, as they are the biggest search engine in the world, they are the most popular, the most used, and the most sophisticated. Local SEO involves having your website rank highly when people enter a location.
Furthermore, there are location based tools, engines and apps that use Google search but with place names allied to the keywords that are entered in the tool/search-bar. If you want to rank highly on these as well, then you will need to pay attention to your local SEO.
Target users in your local vicinity
This is the main reason why you need local SEO, because the people near you are going to search for your business in your local area. For example, if you are a blacksmith then people in your local area are going to want to find your smithy. They will enter the keywords and your local area, and if you have optimized for local SEO then your website will appear on the search engine results page.
Helps users to refine their search results
The user is going to want to be able to narrow down his or her search. One factor that he/she may wish to narrow it down by is location. If your website has sufficient local SEO, then your website will still appear in their search engine results.
Local SEO helps mobile device users find you
People on mobile devices will often use GPS and other mapping technology to find their way around. It is not uncommon for them to do a local search around their area on the map. If your website has local SEO, then not only will people in your area find you, but people on mobile phones who are just visiting will also be able to find you too. This is also a good reason why your website should be dynamic too.