So there's a term that is common in a lot of pedals today, called true bypass and what that means basically, when a pedal is true bypassed the switch, the on off switch on the pedal is basically, it never touches the input of the pedal effect circuitry. So that when it's off, it's almost like the cable is going through the pedal, it's never touching any of the internal circuits.
What that means is that you're getting the cleanest, clearest, possible signal when your pedal is off. What that also means is, if you have a pedal board with a lot of pedals the more pedals that cables have to go through, the less signal loss you're going to have. The more true bypassed pedals that you have, the less chance that your signal is going to get affected by that.
So true bypass pedals have to do with the switch. They're more expensive. Most of the boutique pedals in the $150-200 and up range tend to be true bypass. The cheaper pedals do not. You can always get a cheaper pedal that you like, because a lot of them are great. You can modify them so that they are true bypass. Again possibilities are endless, but that's just to clear up what true bypassed actually means, when you're using pedals in the chain or in a pedal board.