OLTP (Online Transaction Processing) systems are designed for real-time transaction processing, handling large volumes of small transactions, and ensuring high availability and speed. They focus on managing data integrity and providing reliable transaction management. OLAP (Online Analytical Processing) systems, on the other hand, analyze complex queries and multidimensional data models to provide insights into trends and patterns in historical data. The key difference between these two systems lies in their purpose: OLTP for real-time transactions and OLAP for complex data analysis. OLTP typically deals with gigabytes of data, while OLAP handles much larger volumes of terabytes or petabytes of data.