why to use 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: middleware uses

server.use(express.static('./public'));
server.use(express.json());
server.use(express.urlencoded({extended: true}));
const methodOverride = require('method-override');
server.use(methodOverride('_method'));
server.set('view engine', 'ejs');