encode/decode => encode(123456) -> $asdqe&3Ar4$ -> decode($asdqe&3Ar4$) -> 123456 === req.body.password
encode/validate => encode(123456) -> $asdqe&3Ar4$ -> validate($asdqe&3Ar4$ === encode(req.body.password))

bcryptjs
    encode
    validate

app.use(jwt);

/signup
    {username/email, password}
    let hashedPassword = hashPassword(password) //bcryptjs.encrypt(password);
    User.create({username, hashedPassword})


/login
    {username/email, password}
    User.findOne({username: 'test'})
    .then(user => {
       if( bcryptjs.validate(password, user.password) ){
           session.userId = user._id (cookie)
       }else{
           send err;
       }
    })

/profile
    if(session){
        show content
        Profile.findOune({user_id: session.userId})
    }else{
        show an err
    }

JWT
    {data: asdewqeqewasdqeqwewqeads, hash: qwewqeadqweadqwe} => secret('Hayat') => {username: 'asdasd', password: '12313'}