When you come to a conclusion by connecting data with information you already know what are you doing?

The skill of connecting gathered data with information that is known to us is called data analysis. This is a key part of the data analysis process. Example:

It is a fact that foxes are known predators of rats. Lets say you have a data table or observation table that shows the increase in number of rats in your locality versus the increase in the number of fox being spotted by the residents. Now based on the fact that you know, a relation can be established between the increased fox sightings and increase in rat numbers.