Thanks Graham for replying. Production environment means when you make your model live and it starts working on real production data. For example you have prepared a model on Customer attrition in a Bank, have trained it in lower environment. Once user gives you the sign off that model is working fine on trained and test data. Now you need to make this model live ie put in Production environment so that it starts predicting on real life data.

Another example could be a Bank is giving loan to the customer. A new customer joins in. The model built for this will predict whether bank should give loan to the customer or not. Accordingly bank will decide.

Another production example could be, whenever you search for a product on Amzon, it gives some info in the bottom of the page, ‘customer who bought it also bought these’.

Hope I am able to explain my query.