Do I need to create a client module for the central device to establish connection and receive data from a peripheral device?

[developer]

I want to establish BLE connection and have a central device receive data from a peripheral device. I am using the Heart Rate Collector as an example and notice the main file uses a ble_hrs_c.c file that is the client. What is the role of the client module?

[Petter Myhre]

The client on the central communicates with the server on the peripheral.

You can have a server on the central and a client on the peripheral as well.

Some more info here.