Which statement best describes how a hosts file compares to DNS in a network?

• A. It is a local manual mapping on a device, whereas DNS is a distributed resolution system.
• B. It automatically updates domain mappings from the internet.
• C. It caches DNS responses for all devices on a network.
• D. It monitors DNS query traffic to optimize resolution.

Answer: (A)

The main idea here is that a hosts file is a local, manual mapping of names to IP addresses on a single device, while DNS is a distributed system that resolves names across many servers.

A hosts file sits on the device and is read directly by the operating system. You or an admin explicitly add entries there, so the mapping is immediate for that machine and does not rely on any network service. DNS, in contrast, uses a hierarchy of servers to translate names into addresses for the entire network or internet, with resolvers and caches helping to scale the process.

That’s why the description that fits best is: the hosts file is a local manual mapping on a device, whereas DNS is a distributed resolution system.

The other statements don’t fit: the hosts file doesn’t automatically update mappings from the internet; it requires manual edits. It isn’t a shared cache for all devices, so it doesn’t cache DNS responses. It also doesn’t monitor DNS query traffic to optimize resolution; that would be a separate monitoring or analytics activity.