Mongodb Deprecation warning explanation

Deprecation	Value	Explanation
useNewUrlParser	true	parsing: is the process of analyzing simple text and convert it into a more useful format
useFindAndModify	false	by default mongodb allow findAndModify() old methods putting this to false to force the backend to stop using it and use the new methods FindOneAndUpdate()
useCreateIndex	true	ensureIndex() has been deprecated and CreateIndex() is the new version of creating an index for Data
useUnifiedTopology	true	The useUnifiedTopology option removes support for several connection options that are no longer relevant with the new topology engine [Handles monitoring servers]

Nodejs Mongodb configuration

//Connect to DB
mongoose.set('useNewUrlParser', true);
mongoose.set('useFindAndModify', false);
mongoose.set('useCreateIndex', true);
mongoose.set('useUnifiedTopology', true);
mongoose.connect(process.env.MONGODB_URL, (err) => {
    if (!err) {
        console.log('Mongodb has been connected correctly')
    } else {
        console.log(`Error from dataBase connection:${err}`);
    }
});