MOZ

Moz is a tool that you can use for the search engine optimisation of a website. The data that you get from Moz can be used for various SEO purposes, both for on-page SEO and off-page SEO. Furthermore, Moz is a much used tool for link building. 

Moz is mainly known for its Keyword Explorer and Link Explorer. With the Keyword Explorer, you can find and analyze keywords on search volume and difficulty. With the Link Explorer, you have insight into external backlinks and the possibilities of obtaining new backlinks. You can also find information about the domain authority, the spam score, the anchor profile, the page authority and the IP address. 

Moz also offers insight into Your Online Presence. This shows how well the website scores on local searches, so you can improve the regional presence. 

Compared to other SEO tools, such as Ahrefs, Moz is a limited tool. Therefore, Moz is often used for analysing and improving smaller websites. Finally, Moz unfortunately does not have a free version.