To create a computer network, various pieces of hardware are needed to connect devices, manage data flow, and allow communication between different systems. The type of hardware required depends on whether the network is wired or wireless, small (like a home network) or large (like an enterprise system).

A hub is a basic network device used to connect several computers or devices in a network. It receives data from one device and broadcasts it to all other devices connected to the hub, regardless of the destination. This can lead to unnecessary traffic and collisions in the network. Hubs are mostly outdated and have been replaced by more efficient devices like switches.

A bridge connects two separate networks and allows them to communicate as if they are one. It operates at the data link layer and helps control traffic by filtering and forwarding data based on MAC addresses. Bridges are often used to divide a large network into smaller, more manageable segments.

A router is used to connect different networks together, such as a home or office network to the internet. It directs data packets between the networks using IP addresses. Routers can also provide security features like firewalls and often include a switch or wireless access point.

A gateway acts as a translator between different types of networks. It can connect networks that use different protocols (rules for communication). For example, it can connect a local area network (LAN) to a wide area network (WAN). Gateways are more complex than routers and are essential for communication between different systems.

A modem (short for modulator-demodulator) is used to convert digital data from a computer into analog signals that can be sent over telephone lines (and vice versa). It enables internet access over broadband or DSL connections. Most home routers come with a built-in modem. 

A NIC is a hardware component inside a computer that allows it to connect to a network. It can be wired (Ethernet) or wireless.NICs handle the sending and receiving of data and are assigned a unique MAC address for identification on the network.

A WNIC is similar to a regular NIC but allows a device to connect to a wireless network (Wi-Fi) instead of using cables. It may be built into a laptop or added externally via USB or expansion slots. WNICs also use MAC addresses and connect to wireless access points or routers.