What's the difference between Serial DCE and Serial DTE link?

Question

In the Cisco Packet Tracer we also see the Serial DCE and Serial DTE:

but I don't know what's the difference between them.

Answer 1

One side of the link (DCE), has to transmit the clock signal, which controls the data rate, and the other side (DTE) receives the clock signal.

R1 is DCE here:

interface Serial0/0/0
 ip address 10.0.0.1 255.255.255.252
 clock rate 2000000

R2 is DTE here:

interface Serial0/0/0
 ip address 10.0.0.2 255.255.255.252

The difference between the two cables in packet tracer is just which side you click first:

• With the DCE cable, (red zigzag with clock) the side you click first will be the DCE, the second will be DTE
• With the DTE cable (red zigzag no clock) the side you click first will be DTE, the second will be DCE

Whichever way you do it, you'll see one side of the cable shows the clock symbol: this is the DCE.

Answer 2

DCE stands for data circuit-terminating, data communications, or data carrier equipment - this is a modem or more generally, a line adapter.

DTE stands for data terminal equipment which generally is a terminal or a computer.

Basically, these two are the different ends of a serial line.

Answer 3

DATA TERMINAL EQUIPMENT(DTE)

DTE is an end instrument that converts user information into signals or reconverts received signal.These can also be called tail circuits.

DATA COMMUNICATION EQUIPMENT(DCE)

(DCE) refers to computer hardware devices used to establish, maintain and terminate communication network sessions between a data source and its destination.

DCE is connected to the data terminal equipment (DTE) and data transmission circuit (DTC) to convert transmission signals.