Suppose youve ever played a competitive video game and have won games.
In that case, youll probably have seen your opponent blame lag for their loss.
Lag is one form of latency.
Though its not technically the most authentic form, as latency can have multiple definitions.
Latency is a measure of the time difference between cause and effect.
Another way to define it would be the travel time.
Or the propagation delay.
This diagram clearly explains the difference between bandwidth, throughput, and latency.
Contents
Latency in Computer Networking
Computer networking is where the term latency is primarily used.
It has four primary components in non-trivial networks.
These are transmission, propagation, processing, and queueing delays.
The processing delay is the time the receiving devices take to process the transmission.
Generally deciding to pass it on to the next hop in the chain to the true destination.
These nano-second delays add up, especially on transmissions that have to travel further.
Someone living near the server theyre communicating with may see latencies as low as ten or even eight milliseconds.
Local area networks can see sub-millisecond latencies.
The Other Form of Latency
Actual latency is simply the time between cause and effect.
Minor variations can be seen as the route taken might not be identical.
Some component delays may be slightly different on one trip than the other.
Internet users, especially gamers, refer to this round trip time as ping.
A ping is a networking tool that measures the round trip time between the sender and a recipient.
It sends a simple message that generates a standard echo response from the recipient.
This is because it is when the user can first see the result of their action.
This is particularly important in reaction-based scenarios such as most competitive video games.
Where a ping of 100 milliseconds can be a devastating disadvantage.
Other activities like web browsing are much less sensitive to ping.
Even a 500-millisecond ping would be a small part of a page load time.
A Gaming Example
Peekers advantage is an example of the effect of latency from video games.
The attacker has a range of options.
Even fake moves to draw the defenders away.
The attackers other advantage is the peekers advantage, thanks to ping.
Instead, everyone has a window of opportunity, the length of the round trip time.
Where they can act, but the other players cant see it yet.
The attacker can step out from around the corner to gain visibility.
Peekers advantage timeline Credit:Riot
Conclusion
Latency is the delay between a cause and effect.
Technically it is the delay to the actual effect.
The wait until the perceived effect is often referred to in computer networking as latency.
Still, it should more appropriately be called round trip time.
The latency of a connection primarily depends on the distance between both ends.
However, the number of intermediate hops also has an effect.
