how to decide to use which middleware in nest.js

Question

As title.
I am learning Nest.js.
there are many provider in nest ,
such as middleware、pipe、guard、interceptor.
For me ,they are middleware.
How to distinguish their usage scenario.
Thanks all.

Answer 1

each one has its specific usage

for example :

we use Gards when we want to give acces conditions to an end point or a global controller for example we want the service "update user" to be only called by admins (user with role Admin)

we use Pipes to transform the input data to a specific form or to validate some inputs

learn more here in nestJs doccumentation