HTTPS (Hyper Text Transfer Protocol Secure)

Hyper Text Transfer Protocol Secure (HTTPS) is the secure version of HTTP, the protocol over which data is sent between your browser and the website that you are connected to. The 'S' at the end of HTTPS stands for 'Secure'. It means all communications between your browser and the website are encrypted. HTTPS is often used to protect highly confidential online transactions like online banking and online shopping order forms.

URL (Universal Resource Locator

Another name for a web address, the text that you type into your internet browser when you want to go to a website. A URL works like a house address. If you give someone a house address, they can navigate to find a home or business. If you give your browser a URL, it can find where to go to find the web page you want to visit

cURL

cURL is a tool to transfers data from or to a server, using the one of the supporting protocols such as HTTP or HTTPS. You can use cURL to download content from the Internet. 

Postman is a related tool.