Explanation
Because thousands of transactions settle together, cost per transaction drops sharply. You do rely on the bridge and on the mechanism that can challenge faults.
Why a second layer
A blockchain processing everything itself hits a wall: more users means higher costs. A layer 2 processes transactions off the main chain and publishes only a summary plus proof there. That way many transactions share the cost of one posting on layer 1, cutting the price per transaction by a factor of ten to a hundred.
What to watch
Not every layer 2 is equally decentralised. Many still run on a single sequencer ordering transactions, and some have an emergency switch letting a team pause the network. Also check the exit time: on optimistic rollups withdrawing to layer 1 takes seven days by default, unless you use a third-party bridge.
Key takeaways
- Much cheaper, but with extra assumptions.
- Check who runs the sequencer.
- Exit time can be seven days.
Frequently asked questions
+Are my coins on layer 2 the same coins?
They are representations backed by holdings on layer 1. The backing is as strong as that network's bridge and proof system.