Earlier, we mentioned that PHP does not have HTTP request and response message objects, which is why PHP frameworks and coders came out with different abstractions to represent (or "imitate") HTTP messages in the past. Luckily, in 2015, PSR-7 came to the rescue to end these "disagreements" and differences.
PSR-7 is a set of common interfaces (abstractions) that specify public methods for HTTP messages and URIs when communicating over HTTP. In object-oriented programming (OOP), an interface is, in fact, an abstraction of the actions (public methods) that an object (a class) must implement, without defining the complexities and details of how these actions are implemented. For example, the following table shows the methods that your HTTP message classes must implement when composing them so that they comply with the PSR-7 specification.
The specified methods for accessing and modifying the request and response objects...
