To put it simply, ‘contention ratio’ refers to how many users are sharing an amount of network capacity.
A 4 : 1 ratio is great business grade broadband.
In comparison, most residential services are typically 50 : 1, or even higher.
Think of a 1 lane road, if the ratio is 50:1, you could have 50 cars all trying to drive on the road at the same time.
With a 4 : 1 ratio, theres only 4 cars, meaning you will experience less latency and higher throughput.