what is the use of middleware code example

Example 1: middleware uses

const methodOverride = require('method-override');
const { url } = require("inspector");
server.use(methodOverride('_method'));


// middleware
server.use(express.static("./public"));
server.set("view engine", "ejs");
server.use(express.urlencoded({ extended: true }));

Example 2: what is middleware in node js

Notice the call above to next(). Calling this function invokes the next middleware function in the app. The next() function is not a part of the Node.js or Express API, but is the third argument that is passed to the middleware function. The next() function could be named anything, but by convention it is always named “next”. To avoid confusion, always use this convention.