RAID is a way to arrange multiple hard drives to work together so you get better reliability and/or faster performance. It’s a set of disk configurations designed to provide redundancy (so you don’t lose data if a drive fails) and/or enhanced speed. For example, mirroring copies the same data onto two drives, so if one drive fails you can still access everything from the other. Stripping spreads data across multiple drives to boost throughput, increasing read/write speed but typically with less redundancy. Parity-based levels place extra information across drives to allow rebuilding data if a drive fails, balancing capacity, fault tolerance, and performance. Different RAID levels trade off usable capacity, protection against failure, and speed, depending on what you need. RAID can be implemented in hardware with a controller or in software by the operating system. It is not encryption, a networking protocol, or a database indexing method.

Digital citizenship and safe browsing mean acting responsibly online and protecting your personal information while you use the internet. The description that includes respectful online behavior, protecting privacy, using strong passwords, being wary of phishing, and verifying sources is the best fit because it covers both how you interact with others and how you safeguard your accounts and information from scams and misinformation. Relying on antivirus software alone misses the behavioral and information-safety aspects, while using many social networks or ignoring privacy settings can increase risk and erode privacy. In short, responsible conduct online combined with concrete steps to secure accounts and evaluate information embodies safe, smart browsing.

In a home network, traffic is directed between devices and toward the internet by a router. The router is the device that connects your local network to external networks (like your ISP) and decides where to send data destined for different networks. In many homes, this role is fulfilled by a single device that also handles NAT, DHCP, firewall, and often wireless access. A bridge links two network segments at layer 2 and doesn’t route between networks. A hub simply repeats signals to all ports, not directing traffic. A switch forwards frames within the same network based on MAC addresses and doesn’t inherently route to other networks. So the device that also acts as a router is the router.

The common set of rules for exchanging information between devices on a network is a protocol. A protocol defines how data is formatted (syntax), what meaning the bits convey (semantics), and how devices coordinate timing and control signals (timing). This standardization lets different devices and software communicate reliably, even if they’re from different vendors. For example, the HTTP protocol governs how web browsers request pages and how servers respond, including which messages are sent, how errors are indicated, and how sessions are managed. Topology describes the network’s layout, bandwidth is the capacity of the connection to carry data, and latency is the delay in data travel. These are important considerations, but they don’t define the actual rules for exchanging information—that’s the role of a protocol.