Inside the world of flying cars, or eVTOLs, which are moving closer to reality

What if flying around in an electric vehicle is a key part of the way you travel in the future? That's what dozens of companies around the world are betting on.

EVTOLs, or electric vertical take-off and landing vehicles, popularly known as flying cars or air taxis, are being developed by firms in the U.S. to Europe and Asia.

The eVTOL market could be worth $1 trillion by 2040, according to JPMorgan, and several firms are trying to take the lead.

In the latest episode of "CNBC Tech: The Edge" we explore the eVTOL market — its promise and its challenges. Below are some of the companies in the eVTOL space and what they're trying to bring to market.

An eVTOL aircraft can take off and land vertically. And it is, of course, powered by electricity rather than traditional fuel.

There are hundreds of eVTOL designs in the works, with varying technologies. Here's a look at four of the most common.   

The "multicopter" operates like a standard drone. It has multiple propellers that help it fly. They are very efficient during take-off, landing, and while hovering, but because they don't have wings, they're incredibly inefficient at going long distances. They could be useful in urban areas.

The "lift & cruise" concept merges the multicopter with common aircraft technology, like wings, making longer distances possible. But to get the two technologies to work together, the propeller needs fewer and shorter blades — making it very noisy.  

Then there's "tiltrotor" — a design which has one or more rotors mounted on a wing that can tilt up and down.

Finally, there are "ducted vectored thrust" models, which don't have a propeller in sight. They use multiple, individually controlled electrical ducted fans to push the vehicle upward. This model is