What are the differences between bandwidth, network speed, and latency?

In the era of the internet, “slow internet speed” has almost become a universal complaint. Buffering while watching short videos, disconnecting during gaming, choppy video conferences—these are all frustrating experiences. But have you ever wondered what exactly determines “internet speed”? When people talk about internet speed, terms like “bandwidth” and “latency” often come up, but what do these really mean? Why are they so important for our network experience?

Bandwidth

Let’s start with bandwidth. Imagine your home network is like a highway, and data is the vehicle traveling on it. Bandwidth, in simple terms, is the width of this highway. The wider the highway, the more vehicles can travel at the same time, and the more efficient data transmission becomes.

Technically, bandwidth refers to the amount of data a network can transfer in a given period of time, typically measured in bits per second (bps). Common units also include Mbps (megabits per second) and Gbps (gigabits per second). For example, if your broadband speed is 100Mbps, this means that in theory, the network can transfer 100 megabits of data per second.

However, there’s something important to clarify: 1Mbps does not equal 1MB/s (megabytes per second). Since 1 byte (Byte) equals 8 bits (bit), a 100Mbps bandwidth theoretically allows a maximum download speed of 12.5MB/s. This is why, even if you have a 100M broadband connection, your download speed might only be around 10MB/s.

Bandwidth is like the water pipe in your house— the thicker the pipe, the more water can flow through it. Watching 4K videos, playing large online games, and downloading large files all require more bandwidth. If the bandwidth is insufficient, it’s like having a narrow pipe where the water flow is slow, causing video buffering or frame drops in games.

But bandwidth is not everything when it comes to internet speed. Many people think that upgrading to a 1000M broadband connection will vastly improve their internet experience, but this is not always the case. This is because, apart from bandwidth, other factors such as latency, packet loss, and even the performance of your devices also affect your network experience.

One often overlooked point is that bandwidth is shared. If multiple people in your household are using the internet at the same time—for example, you’re watching a movie, your roommate is playing a game, and your parents are browsing short videos— the data demands of all devices will compete for that “highway.” The same applies to the network of your ISP. The more users are online in your neighborhood, the less bandwidth your home may be allocated. This is why internet speed often slows down during peak hours in the evening.

Internet Speed

Now that we’ve talked about bandwidth, let’s discuss internet speed. Internet speed is a broader concept, referring to the actual speed at which you experience data transfer. Many people confuse internet speed with bandwidth, but internet speed is affected by multiple factors, including bandwidth, latency, and packet loss.

Internet speed directly determines how quickly you can open websites, load videos, and download files. For example, when you test your internet speed with a tool like Speedtest, the result typically includes download speed, upload speed, and latency. Download speed reflects how quickly you can retrieve data from a server, such as when watching videos or downloading files. Upload speed indicates how quickly you can send data to a server, like when sending an email or uploading a video to the cloud.

Bandwidth is the theoretical upper limit of your internet speed, but your actual internet speed is often lower than the theoretical bandwidth. For instance, your home may have 100Mbps broadband, but a speed test might show only 80Mbps or even lower. This is due to various “losses” during network transmission: the performance of your router, server response time, network congestion, and even the strength of your home Wi-Fi signal can all slow down the internet speed.

For example, imagine you’re dining at a restaurant. Bandwidth is like the kitchen’s ability to cook multiple dishes at the same time, while internet speed is the actual speed at which you receive your food. If the waiter (the router) is slow or the path between the kitchen and your table (the network path) is blocked, no matter how quickly the kitchen prepares the dishes, you’ll still be waiting longer.

In addition to bandwidth, several other factors can influence your internet speed:

• Device performance: If your computer, phone, or router has low specs or poor data processing capabilities, your internet speed will be slower.
• Network congestion: Just like mentioned earlier, during peak hours in the evening when everyone is online, the pressure on the server and network lines can slow down your internet speed.
• Server distance: The farther the server you’re accessing is from you, the longer the data transmission journey, which can result in slower speeds.
• Wi-Fi interference: If your home Wi-Fi signal is interfered with by walls, appliances, or even conflicts with your neighbor’s Wi-Fi channels, your internet speed will decrease.

So, slow internet speed isn’t always a result of insufficient bandwidth. You may need to check other factors as well.

Latency

Next, let’s talk about latency. If bandwidth is the width of the highway and internet speed is the vehicle speed, then latency is the time it takes for a car to travel from the starting point to the destination. The lower the latency, the faster the network response.

Latency refers to the time it takes for data to travel from your device to the server and back, typically measured in milliseconds (ms). The “Ping value” shown on speed test tools is an example of latency. The lower the Ping value, the faster the network response.

Latency has a significant impact on real-time activities. For example:

• Online gaming: High latency causes delayed actions, and might even lead to disconnects.
• Video conferencing: High latency causes out-of-sync conversations and choppy video.
• Real-time trading: For activities like stock trading or flash sales, high latency may cause you to miss critical moments.

Main Causes of Latency:

• Physical distance: Data takes time to travel across the network, so the farther the server is from you, the higher the latency. For example, visiting domestic websites usually results in latency of 20-50ms, while visiting overseas websites might have latency of 200ms or more.
• Network devices: Devices like routers and switches need time to process data. Poor device performance or improper configuration can increase latency.
• Network congestion: When network traffic is high, data packets need to queue up, which naturally increases latency.
• Signal quality: When using Wi-Fi, weak signals or interference can slow down data transmission, increasing latency.

The Relationship Between Bandwidth, Internet Speed, and Latency

Now that we understand the meaning of bandwidth, internet speed, and latency individually, how do they work together to influence the overall network experience?

Simply put:

• Bandwidth determines the “volume” of data transmission, which is the theoretical maximum limit for your internet speed.
• Internet speed is the actual transmission speed you experience, which is influenced by bandwidth, latency, device performance, and other factors.
• Latency determines how quickly data can be transferred, and is especially important for real-time applications.

Here’s a real-world analogy: Imagine you’re moving houses. Bandwidth is the size of the truck you rent, internet speed is how quickly you move your belongings, and latency is the time it takes for the truck to travel from your old house to the new one. If the truck is very large (high bandwidth), but the road is congested (high latency), your moving efficiency won’t be high. Likewise, if the truck is small (low bandwidth), even if the road is clear (low latency), you won’t be able to move much.

How to Optimize Your Network Experience

Now that we understand these concepts, how can we improve our network experience?

Here are a few practical tips:

1. Choose the right broadband plan: Select a bandwidth that suits your needs. For example, 100Mbps is sufficient for browsing and watching standard-definition videos, but for 4K videos and large games, 500Mbps or higher is recommended.
2. Optimize your Wi-Fi environment: Place your router in an open area to avoid obstructions like walls. Adjust Wi-Fi channels to avoid interference from neighbors.
3. Upgrade your devices: Older routers or computers may slow down internet speed, so consider upgrading your hardware.
4. Use wired connections: Ethernet connections are more stable and have lower latency compared to Wi-Fi.
5. Monitor network usage: If multiple people are using the internet at home, limit bandwidth usage on certain devices by using the router’s Quality of Service (QoS) features.
6. Choose a good service provider: Different ISPs offer varying network quality. Look at user reviews to choose one with a good reputation.