Sure! Here's an SEO-friendly HTML answer for the interview question "What is the difference between alternating current (AC) and direct current (DC)?":

```html

The Difference Between Alternating Current (AC) and Direct Current (DC)

Alternating current (AC) and direct current (DC) are two types of electrical currents with distinct characteristics:

• AC: Alternating current is a type of electrical current that periodically changes direction, typically found in power grids and household outlets.
• DC: Direct current is an electrical current that flows in one direction, commonly used in batteries and electronic devices.

Key differences between AC and DC include their direction of flow, applications, and efficiency in transmission.

```

Focus Keyword: **Difference Between Alternating Current (AC) and Direct Current (DC)**

This HTML snippet provides a brief and informative overview of the differences between AC and DC, which can help improve visibility for search engines looking for information on this topic.