Differentiate between brown out and power surge as used in a computer

A surge in electrical power means that there is an unexpected increase in the amount of voltage provided. This can be a small increase or a larger increase known as a spike. A spike is a short transient in voltage that can be due to a short circuit, tripped circuit breaker, power outage, or lightning strike.

A sag is an unexpected decrease in the amount of voltage provided. Typically, sags are limited in time and in the decrease in voltage. However, when voltage reduces further, a brownout could ensue. During a brownout the voltage drops to such an extent that it typically causes the lights to dim and causes computers to shut off.

A blackout is when a total loss of power for a prolonged period occurs. Another problem associated with blackouts is the spike that can occur when power is restored. In the New York area, it is common to have an increased amount of tech support calls during July; this is attributed to lightning storms! Quite often this is due to improper protection.

Explanation:

A surge in electrical power means that there is an unexpected increase in the amount of voltage provided. ... During a brownout the voltage drops to such an extent that it typically causes the lights to dim and causes computers to shut off. A blackout is when a total loss of power for a prolonged period occurs.

A blackout is a complete interruption of power in a given service area. Rolling blackouts are controlled and usually preplanned interruptions of service. A brownout is a partial, temporary reduction in system voltage or total system capacity..

A Power Surge is a short-term high voltage increase of more than 110 percent. Typical causes include outages, lightning strikes or other power malfunctions caused by utility companies. ... A Brownout (or power sag) is a short-term low-voltage deficiency that occurs when the demand for power exceeds supply.