A PI Historian is a real-time data historian developed by OSIsoft. The PI Historian records data values over time in a proprietary time-series database. All different types of data can be recorded and each distinct piece of data is known as a PI tag. For a given PI tag, you record its events or data values over time.What is the PI Server?
The PI Server includes sophisticated (but easy to use) calculation tools that transform raw data, combine data values from multiple systems into robust analyses, automate calculation of vital day-to-day metrics, and deliver new insights.What is the PI Data Archive feature?
The PI Data Archive feature makes for fast and secure data storage. It archives a compressed version of a manufacturer’s historized data, storing five times  more data without overloading the server. The Data Archive feature also utilizes the client computer’s Microsoft Security, enhancing overall data security.Why is OSIsoft Pi historian the king of the historian market?
Here are four (4) reasons why OSIsoft’s PI Historian is widely viewed as the king of the historian market: Most historians require additional 3 rd party software to establish a connection. This requirement acts as a “middle man” and creates a bottleneck in the process.