What is difference between geolocation & GPS?

Question

which we used in mapping in website to link our location

Answer 1

One is used to get location data from your device if the user permits. The other is a hardware component (GPS receiver) which gets location data from nearby satellites orbiting earth.

It's geolocation API which gets location from your device. But the target device needs to have GPS receiver to send relevant data through the API.

Read more about Geolocation API:
https://en.wikipedia.org/wiki/W3C_Geolocation_API
https://developers.google.com/maps/documentation/geolocation/intro
https://developer.mozilla.org/en-US/docs/Web/API/Geolocation/Using_geolocation

Read this article for info about GPS:
https://en.wikipedia.org/wiki/Global_Positioning_System
https://en.wikipedia.org/wiki/GPS_navigation_device

A useful tip: if you get curious consider doing some research using a search engine. It will benefit you greatly. [two listed below]
http://www.qwant.com/
https://duckduckgo.com/

That's all! Good Luck 🍀

Update: if you don't mean the api(you mentioned web site in description..) then read the below article it explains in simple words about geolocation. Not adding more info the post will be too big.
https://www.techopedia.com/definition/1935/geolocation

Answer 2

When a GPS signal is unavailable,  geolocationapplications can use information from cell towers to triangulate the approximate position, a method that is not as accurate as GPS but has greatly improved in recent years. ... The word geolocation also refers to the latitude and longitude coordinates of a particular location.