What's the difference between OLTP and OLAP?

This two words which both starts with the letters OL, both ends with the letter P, and both consists of four letters are very much different IT/BI(Business Intelligence) jargons.

How are they different?
By Definition :
OLTP which stands for Online Transaction Processing or simply transaction processing is a class of systems that facilitates and manages transaction-related applications and provide real time accesses to its data which is being updated by other transactions. It is also used to refer to a processing wherein the system can quickly respond to user requests/transactions.

OLAP which stands for Online Analytical Processing refers to an approach to quickly provide answers to analytical queries that are multi-dimensional in nature. Through the use of what they call Aggregations, some have claimed that for complex queries, OLAP cubes can produce an answer in around 0.1% of the time for the same query on OLTP relational data.