Internet Speed: Bandwidth and Latency, Up- and Download
Have you ever noticed that some websites load faster than others? Or that it takes longer to send a big file than a small one? This is because of two things: bandwidth and latency.
Bandwidth: The Width of the Pipe
Bandwidth is the amount of information that can travel over the internet at one time. Think of it like a water pipe. A wide pipe can carry more water than a narrow one. A wide “pipe” of bandwidth means more information can reach your computer quickly.
Latency: The Delay
Latency is the time it takes for a single piece of information to travel from one computer to another. Imagine you’re playing catch with a friend. Latency is the time it takes for the ball to travel through the air between you. If you’re standing far apart, there’s more latency! In online games, high latency is often called “lag.”
How is Speed Measured?
We measure internet speed in Mbps, which stands for Megabits per second.
- One bit is a tiny pulse of electricity or light—the smallest unit of information.
- A Megabit is one million of those tiny pulses! If your speed is 100 Mbps, it means your connection can handle 100 million bits of information every single second.
Upload vs. Download
There are two ways that information moves on the internet:
- Download: This is when information comes from a server to your computer—like when you’re watching a video or opening a web page.
- Upload: This is when you send information from your computer to a server—like when you send an email or post a picture on social media.
Usually, downloading is much faster than uploading! This is because most people spend more time watching videos or reading websites (downloading) than they do sending large files (uploading).
What Affects Your Speed?
Many things can slow down your internet:
- The Number of Devices: If everyone in your house is watching a movie at the same time, they are all sharing the same “pipe.” This means there is less bandwidth for everyone!
- Connection Type: Using a wire (Ethernet) is usually faster and more stable than using Wifi.
- Distance: If you are far away from your Wifi router, the signal gets weaker and slower.
Did you know?
- Ping: We measure latency in milliseconds (thousandths of a second) and often call it a “ping.” A ping of 50ms means it takes 0.05 seconds for data to travel to a server and back!
- The Speed of Light: Information on the internet travels through fiber-optic cables at the speed of light, which is about 300,000 kilometers per second!
- Buffer: When a video stops and shows a spinning circle, it’s called “buffering.” Your computer is waiting for more packets to arrive because the bandwidth isn’t fast enough to keep up with the video.
- First Speed: Back in the 1990s, internet speeds were often around 0.056 Mbps. Today, many homes have speeds of 100 Mbps or even 1,000 Mbps!
Check Your Knowledge
- What is the difference between bandwidth and latency?
- What does Mbps stand for, and what does it measure?
- Why might your internet feel slower if your whole family is using it at once?
- If you are sending a video to a friend on Discord, are you mostly uploading or downloading?
- Why is an Ethernet cable usually better for gaming than Wifi?