1. Web APIs
In computer programming, an application programming interface (API) is a set of subroutine definitions, protocols, and tools for building application software.

2. application programming interface (API)
In general terms, it is a set of clearly defined methods of communication between various software components.
A good API makes it easier to develop a computer program by providing all the building blocks, which are then put together by the programmer.
An API may be for a web-based system, operating system, database system, computer hardware or software library.

3. REpresentational State Transfer (REST) is an architectural style that defines a set of constraints and properties based on HTTP.
GET
PUT
PATCH
POST
DELETE
List the details of an entity or collection. Retrieve a representation of an entity
Replace an entity or an entire collection
If entity or collection does not exist, create it.
Update an entity in a collection.
Create a new entity or collection.
Delete a entity or a collection

4. In computer programming, create, read, update, and delete (as an acronym CRUD) are the four basic functions of persistent storage.
Operation
SQL
HTTP
DDS
Create
INSERT
PUT / POST
write
Read (Retrieve)
SELECT
GET
read / take
Update (Modify)
UPDATE
PUT / POST / PATCH
Delete (Destroy)
DELETE
dispose