What Is Difference Between Buy And Purchase?

Purchase is used for contracting and consulting acquisition, and might be a short-term good or service. "Buy" is physical such as consumable goods. Normally, you own something you buy, but when you are having the service of something by some one you usually "purchase" it for some time.

But nowadays this difference is not catered you can use what ever you want to.

Difference are
1)Buying involves the two person's direct involvement one is the buyer and the other is the seller.
Where as in purchasing two entity involves comprising of many persons.
2)No supplementary documents are required for buying whereas purchasing requires supplementary documents.

If you want to own something you have to buy and to obtain some thing you have to purchase.

I think buy and purchase have same meaning, the only difference is purchase tend to be a little bit formal.

Buy means , you can resell the product end purchase means you can not sell the product

Purchase denotes equitable title, buy denotes legal title.