TLD is stand for top level domain. LTDs domain name located on the right side of the dot ("...")the most common LTD is used to a .com, .net, .org, .biz, etc. these common LTD all have special guidelines generally available on registrar anywhere in the world.
ccTLD is a country code top level domain extension that is show to a country in the world. Each country has their own domain extension based on their country code. Eg .US (United States), .UK (united kingdom), .CA (Canada), .IL (Italy), .PK (Pakistan) etc
The domain biz, and pro are also considered generic however, these are named as limited, because the registrations within require the proof of eligibility within the guidelines. gTLD stands for generic Top Level Domain and is a common term used in the domain industry. It refers to all the domain extensions that are not assigned to a specific country (ccTLD). GTLDs are mostly unrestricted and because of their generic nature and availability, used by people worldwide.
nTLD is stand for new top level domain extension term used in the domain industry. it refers to all the domain extension that are not assigned to a specific country(ccTLD) example .store, .club, .guru etc.