These are often referred to as citation sources or backlinks and they are popularity votes in Google’s eyes.
The backlinks you have from powerful websites and the more relevant to your main topic the more SEO power you will gain.
The most important ones are directories that are related to your niche and local directories if your customers are near your business. There are some online submission services like Moz Local, Yext and BrightLocal to name a few that automate the process. Although paying for and automating directory submissions might save time, doing them manually would be would be my suggestion for getting the best value. For manual citations you can change up the text for each business description making it unique and not a copy, add optimized images, team member’s profiles, additional business categories and more.
Google does not always index all of these new profile pages and if they are not indexed they they wont count. Adding a page like this that links to my profiles helps Google crawl these and they will more likely be indexed and count.
If you would like to know more about backlinks or SEO in general lets set up a call.