Bluetooth TTL to Arduino

Hi all!

I need to connect a TTL bluetooth module with shield to my arduino.

I bought this module:

It's the TTL module, but i see this other module:

Serial bluetooth module:

In the serial, the "TX" from the bluetooth it's going to connect to "RX" in arduino, and the "RX" of the bluetooth i need to connect to "TX" in arduino.

What is the correct form to connect the TTL bluetooth module to arduino?

I have this documentation.

In the page 5, i can see the connections for the serial module, but the TTL??? 3.3V logic level??? what is this?

Thanks very much!