Http Response COdes

= Server whenever sends the response to the client, http response code willbe send to the client

100-199 -> Not Needed

200-299 -> Success Response Code
    200 => SUCCESS, OK
    201 => Created,
    204 => No Content

300-399 -> Redirection Related Response codes
    301 => Permanent Redirection

400-499
    400 => Bad Request
    401 => Unauthorized
    403 => Access Denied
    404 => Not Found
    405 => Method Not allowed
    408 => Request time out
    422 => Unprocessable Entity
    429 => Large payload

500-599 -> Related to server error
    500 => Internal Server Error
    502 => Bad Gateway
    503 => Service unavailable
    504 => Gateway timeout

Middleware executes at diffferent level ->To manipulate the request before your action call ->To respond to the client/end the request ->Call next middleware/action call

-> Garbage collector
-> Handle routes

->Every middleware function accepts 3 parameters(compulsary)

a. Application Level Middleware -> app.user(mount) or expressApplication.method(load) //this is always application level middleware app.get("/", (req, res, next)=>{})

b. Routing Level Middleware ->mounted to express.Router() -> app.use()

c. Custom Middlware -> We normally mount custom middlwar to the route path

d. Third Party Middleware => multer ==>multipart/form-data

e. Bultin Middlware express.json() => json content express.static() express.urlencoded()

f. Error Handling Middleware //sabai vanda last ma rakhna parcha