Both of these chainsaws are produced by the same company and have almost the same feature, so it is often hard to understand the differences.
The reviews above make it pretty clear about the differences. But if you are still having trouble understanding the difference, here are more.
The major difference between these two chainsaws is that the Husqvarna 440 chainsaw requires a T-wrench if you want to adjust the chain tension. However, the Husqvarna 440e chainsaw does not require such a tool.
The Husqvarna 440e is a tool-free chainsaw. That means you don't need to keep your eye on the tool to adjust the chain. But you have to do it if you are using the Husqvarna 440.
Another little difference between these two chainsaws is the length of the bar. The 440 chainsaw bar length is 18 inches in diameter, whereas the 440e has inches.