Daily Junction.mobi portalTechnology · August 3, 2023 · Liam Chen · 6 min
Latency is the delay between asking for data and starting to receive it. Here is what causes lag, why it is different from bandwidth, and why it matters so much for calls, gaming and the web.
You have a fast broadband plan, yet a video call still stutters or an online game feels sluggish. The culprit is often not a lack of speed but latency, the hidden delay that shapes how responsive your connection feels. It is one of the most important and least understood measures in networking.
Here is what latency is and why it matters.
Latency is the delay between sending a request and the first part of the response arriving, usually measured in milliseconds, written as ms.
In plain terms, it is the lag in a connection. When you click a link, send a message or move in an online game, your request travels across the network to a server and the reply travels back. Latency measures the round trip of that conversation. The lower the number, the snappier everything feels.
You may also see latency described as ping, the name of a tool that measures it. A "low ping" simply means low latency, which is why gamers prize it.
The single most useful thing to understand is that latency and bandwidth measure different things, and confusing them leads to a lot of frustration.
A classic analogy is post. Imagine sending a thousand letters by lorry versus a single urgent note by motorbike courier. The lorry has huge capacity, lots of bandwidth, but takes a long time to arrive, high latency. The motorbike carries almost nothing yet arrives in minutes, low latency. For a quick reply, you want the courier; for moving a mountain of post, you want the lorry.
This is why a connection with plenty of bandwidth can still feel laggy. If each request takes a long time to make the round trip, the experience is poor no matter how wide the pipe. For the other side of this story, see our guide to bandwidth.
Latency builds up from several sources along the path your data takes. The main contributors are:
Every one of these adds milliseconds, and they stack up across the round trip.
Whether latency matters depends entirely on what you are doing. For some tasks it is barely noticeable; for others it makes or breaks the experience.
Latency matters most for real-time activities, where a back-and-forth happens constantly:
Latency matters far less for tasks that move a lot of data in one go, such as downloading a large file or streaming a film once it has buffered. There, bandwidth is the bigger factor, because a short initial delay barely registers across a long transfer.
A useful rule of thumb: bandwidth decides how fast you can move a lot of data, while latency decides how responsive everything feels moment to moment.
There is no universal threshold, but lower is always better. As a rough guide, latency under about 50 milliseconds feels responsive for everyday use, and competitive gamers chase figures lower still. Once latency climbs into the hundreds of milliseconds, delays become noticeable in calls and games.
You can get a sense of your own latency with a simple online speed test, which usually reports a ping figure alongside your download and upload speeds. If that number is high even when nothing else is using the connection, the cause may be your connection type, your distance from servers, or congestion.
You cannot beat physics, but a lot of effort goes into trimming latency where possible. Common approaches include:
Small improvements at each stage add up to a connection that feels noticeably more responsive.
Latency is the delay between making a request and the first response arriving, measured in milliseconds, and it is what makes a connection feel snappy or sluggish. It is not the same as bandwidth: latency is about delay, bandwidth is about how much data flows at once, and a fast connection can still feel laggy if latency is high.
Distance, network hops, congestion and your connection type all add to it. Low latency matters most for real-time tasks like calls and gaming, and less for big downloads. Understand the difference, and you will know whether your next connection problem calls for more bandwidth or for lower latency, the quiet number that shapes so much of how the internet feels.
![[View image]](/img/what-is-latency.jpg){kind=link}