Types of GEOIP? Free solutions?

Question

User identification

It is necessary to make a definition by the IP of at least the country.
As I understand it, there are 2 options: definition on the server side, when I have access to the database / definition service; and client-side detection when the browser makes an Ajax request to a third party providing the service.
1. What are the advantages of each method?
2. Are there free or moderately priced services?

Answer 1

1. as you prefer
2. Maxmind, there is a free solution which is enough for a typical system. Scripts for converting to bases and other formats are on GitHub