I just started learning about passport but I'm not getting why do we need to write passport.serializeUser(User.serializeUser()); and passport.deserializeUser(User.deserializeUser());.
const userSchema = new mongoose.Schema({
username: String,
password: String
});
//using passport-local-mongoose plugin
userSchema.plugin(passportLocalMongoose);
const User = mongoose.model("user", userSchema);
passport.use(User.createStrategy());
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());