Does recall has different interpretation when comes to classification and information retrieval

Question

Recall Definition

In terms of classification

The recall is defined as no of positive instances that are correctly detected by the classifier.

$$ TP = \frac{TP}{(TP+FN)} $$

In terms of Information retrieval

Recall is defined as No of relevant documents that are retrieved.

 Let p = No of relevant documents that are retrieved   and
     q = Total number of relevant documents 

 Formula  = p/q   

Do both the definition work on any common understanding?. I still can't get my head through this. If both are different, why are they using the same name recall?