Describe how direct current differs from alternating current.

Explanation

### Step-by-Step Solution:

1. **Definition of Direct Current (DC)**:
- Direct Current (DC) is a type of electrical current that flows in a single direction. The flow of electrons is constant, meaning that the positive and negative terminals of the source (like a battery) remain fixed.

2. **Characteristics of DC**:
- In DC, the polarities (positive and negative) of the source are fixed. For example, in a battery, the positive terminal is always positive, and the negative terminal is always negative.
- The direction of current flow is also constant; it always moves from the positive terminal to the negative terminal.
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