In networking, what does the term 'subnetting' refer to?

Subnetting refers to the process of dividing a larger network into smaller, more manageable sub-networks, or subnets. This is done to improve network performance and security by limiting broadcast traffic and segmenting traffic among different subnetworks. Each subnet can operate independently, which helps in better organization and easier management of IP address allocation.

By creating these smaller networks, subnetting enables efficient utilization of IP addresses and helps in reducing congestion within the larger network. Each subnet can also be tailored to meet specific needs, such as different security protocols or network policies. Additionally, subnetting plays a crucial role in routing as it enables routers to make decisions based on which subnet a packet should be forwarded to, optimizing the overall traffic flow.

The other options pertain to different concepts in networking. Combining multiple networks into one refers to network aggregation, which is not the focus of subnetting. Encrypting data packets deals with data security rather than network structure, and testing network speed and performance is more related to network analysis rather than the structuring of IP addressing through subnetting.