Which two categories of network cables are primarily used today?

Copper and fiber are indeed the primary categories of network cables used today. Copper cables, such as twisted pair cables (which include both unshielded and shielded varieties), are widely utilized for local area networks (LANs) due to their cost-effectiveness and ease of installation. This type of cable effectively transmits electrical signals over short distances, making it suitable for connecting various devices within a network.

Fiber optic cables, on the other hand, are constructed with strands of glass or plastic that transmit data as pulses of light. This allows for significantly higher bandwidth and longer distances compared to copper cables, making them ideal for backbone connections in larger networks, as well as for internet infrastructure. The use of fiber optics continues to grow as demand for higher-speed data transmission increases.

The other options mentioned do not fully capture the two main categories of cables in use today. For instance, while coaxial cables have been important in the past, particularly in older television and broadband data systems, they aren't primarily used for most modern network infrastructure compared to copper and fiber options.