It’s the weakest link in the chain explanation. Your connection to your ISP can be at X speed, but if their connection to the service you’re using is at Y speed, you’re only going to get Y speed. Also, if you’re using wifi or a crappy router or old cables or too many people in your area are using the same ISP, that can all affect your speed as well.
Also different devices will have different top speeds. A hardwired PC and a wifi connected cell phone will have drastically different top speeds.
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