What are global top level domains (gTLDs)?Generic top level domains are the set of domains you can use to register under, which are not country-specific, and are therefore global in scope. Historically these were limited to .com, .net, .info, .org and a few other domains, but recently they have been expanded massively (and continue to expand) to encompass many different domains. The new generic top level domain (gTLD) application system opened in 2012 and in 2013 the first of these domains, like , started to appear. Many large tech companies have chosen to register gTLDs for their own use - like Amazon (.book and 75 others), Google (.google and 100 others), and Microsoft (11 domains). Many other companies have applied to register gtlds in the hope of selling registrations to them.
What are country specific domains?
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code.
How are gTLDs different from country code domains?
Google will treat your domain differently if it is a gTLD as opposed to a country one. Searches from all countries will come to this domain, but it will have less weight for searches in a specific country. You should also consider the impact on users of using a gTLD compared to a country domain.
So if you want to show up for searches just in one country, and don't care about others, you might want to consider a country-specific domain, otherwise you're probably best to pick a global domain.