Introduction:
A demultiplexer, also known as a data distributor, is a digital circuit that takes one input and distributes it to one of several outputs based on the control signals. It is the opposite of a multiplexer, which takes multiple inputs and selects one output.

Explanation:
The reason why a demultiplexer is called a data distributor is because it distributes the input data to one of the outputs based on the control signals. Let's understand this in more detail:

1. Input Distribution:
- A demultiplexer has one input and multiple outputs.
- When a data signal is applied to the input, it is distributed to one of the outputs based on the control signals.
- The control signals determine which output will receive the input data.

2. Control Signals Selection:
- The demultiplexer has control inputs that are used to select one of the outputs.
- These control inputs determine which output will be active and receive the input data.
- For example, if there are 2^n outputs, n control inputs will be required to select one of the outputs.
- The control inputs can be set to binary values, and each combination of control inputs will select a specific output.

3. Output Distribution:
- Once the control inputs have selected a specific output, the input data is distributed to that output.
- The selected output will receive the input data, while the other outputs remain inactive.
- This distribution of input data to one of the outputs is why a demultiplexer is called a data distributor.

4. Single Input, Multiple Outputs:
- A key characteristic of a demultiplexer is that it has a single input and multiple outputs.
- This means that the demultiplexer can take a single data signal and distribute it to different destinations.
- Each output represents a different destination for the input data, and the demultiplexer decides which output will receive the data based on the control signals.

Conclusion:
In summary, a demultiplexer is called a data distributor because it takes a single input and distributes it to one of the outputs based on the control signals. The input is distributed to the selected output, while the other outputs remain inactive. This characteristic of a demultiplexer makes it a useful circuit for distributing data to multiple destinations.