Pod vape devices have been making a big comeback for small, low-power stealth devices. While most people prefer to vape with higher power levels for the flavour, they don't always want the cloud that comes with it. Pods effectively solve the cloud problem without too much of a sacrifice in flavour compared to the low-power devices of the past.
With the newer technology now available, the same power that used to require a pen-style battery has been slimmed down to just over the size of a credit card with the Suorin Air, or down to the size of a flattened pen with the Limitless Pulse. The juice capacity is on the smaller side, but with the lower vapour output, you'll be switching to a higher nicotine level to accommodate. This means you use less ejuice in a day.
Instead of filling a tank, you refill the pod until the coil inside burns out from use. Then you throw the pod out and replace it with a new unit. The cost is still comparable to a standard coil, despite the added materials. Pod vape devices are great for people just starting out that want a tight draw like they're used to with cigarettes, or they're also nice as a secondary vape for people that just want something pocketable to go out with. Either way, you may want to have a look for yourself and see if a Pod system is right for you.