OLTP databases are meant to be used to do many small transactions, and usually serve as a "single source of truth". OLAP databases on the other hand are more suited for analytics, data mining, fewer queries but they are usually bigger (they operate on more data).

What is OLTP used for?

OLTP, or online transactional processing, enables the real-time execution of large numbers of database transactions by large numbers of people, typically over the internet. A database transaction is a change, insertion, deletion, or query of data in a database.

What are the basic reason for OLTP?

Online transaction processing applications have high throughput and are insert- or update-intensive in database management. These applications are used concurrently by hundreds of users. The key goals of OLTP applications are availability, speed, concurrency and recoverability.