Subnetworks in a network architecture are primarily used for what purpose?

Subnetworks, or subnets, are utilized in network architectures primarily to create distinct functional segments with controlled access. This segmentation enhances security and performance by isolating different areas of the network based on their specific roles or functional requirements. For instance, a network might be divided into subnets for different departments within an organization, such as finance, human resources, and IT. Each subnet can have tailored access controls, limiting which users can access certain resources based on their roles.

Implementing subnetting allows for improved management of network traffic and the application of specific security measures to each segment. This means that even if a breach occurs in one subnet, the impact can be contained without affecting other parts of the network. Furthermore, it aids in efficient IP address management and can help boost overall network performance by reducing congestion.

The other choices do not accurately reflect the primary purpose of subnetting. Unrestricted access across an entire network can lead to security vulnerabilities; centralizing user authentication is not the main focus of subnetting; and while connectivity among devices is important, the creation of distinct segments is essential for security and management rather than ensuring full connectivity.