Final answer:
GFIs are designed to prevent electric shocks, and AFCIs are designed to prevent fires by detecting unintended electrical arcs.
Step-by-step explanation:
GFIs are designed to prevent electric shocks by detecting imbalances in electrical current, specifically the loss of current to unintentional paths. If a difference is detected, indicating a leakage current that could present a shock hazard, the GFI trips to interrupt the flow of electricity. This protection is crucial in locations where electrical equipment is near water, such as bathrooms and kitchens. On the other hand, an isolation transformer also serves to prevent shock by insulating the device being powered from the original source, which can prevent the inadvertent creation of a hazardous path for current flow.
Arc-fault circuit interrupters (AFCIs) are designed to protect against fires by detecting an unintended electrical arc, which can generate enough heat to cause a fire. Unlike ordinary circuit breakers and fuses which are designed to protect against overcurrent and short circuits to prevent thermal hazards, AFCIs provide additional protection by identifying potentially dangerous arc faults and interrupting the circuit.