Bandwidth is the capacity of your network connection. Think of it like the width of a water pipe: a wider pipe lets more water flow through at once. In networking, it determines how much data can move between your device and the internet simultaneously.
Bandwidth is measured in bits per second. Common units include:
- Mbps (megabits per second): standard for home broadband
- Gbps (gigabits per second): for faster connections like fibre or modern routers
Real-world example: if your connection has 50 Mbps bandwidth, you can download a 50-megabit file in one second, or stream a 5 Mbps video while using 20 Mbps for other activity and still have capacity left over.
Your internet service provider advertises bandwidth as a headline number (like "100 Mbps broadband"). In practice, you won't always achieve the advertised speed because of network congestion, distance from the exchange, and the quality of your equipment. Multiple devices on the same connection share the bandwidth: streaming video, video calls, and large downloads all compete for the same pipe.
When choosing broadband or upgrading your router, bandwidth matters because it affects what you can do simultaneously. Light users (email, browsing, social media) need less bandwidth. Households with multiple people streaming video, gaming online, or working from home need substantially more. If you frequently notice slow speeds even with modern equipment, your bandwidth limit is probably the bottleneck.