So what's the main difference between detection and recognition? Consider face detection and face recognition. In face detection, the algorithm tries to detect a face from an image, but in recognition, the algorithm can also state information about whose face is detected. It may be the person's name, gender, or something else.
Similarly, object detection involves the detection of a class of object and recognition performs the next level of classification, which tells which us the name of the object.
There is a vast number of applications that use object detection and recognition techniques. Here is a popular application that is going to be used in Amazon warehouses: