One-time fuses are designed to be used once and then discarded, while resettable fuses can be used multiple times. One-time fuses are made of a material that melts when exposed to too much current, causing an electrical circuit to break. On the other hand, resettable fuses contain a metallic element that expands when too much current flows through them. This expansion causes the element to push against the sides of the fuse, opening the circuit. Once the current is cut off, the element cools and contracts, allowing the circuit to be closed again. One-time fuses are typically more affordable than resettable fuses, but they need to be replaced after each use. On the other hand, resettable fuses can be reused multiple times before they need to be replaced.