A hybrid car uses two forms energy - gasoline and electricity - for propulsion in an effort to keep CO2 emissions to a minimum and maximize fuel economy.
A regular hybrid (examples are the Toyota Prius and Lexus NX SUV) has a conventional engine which can propel the car directly, while also charging a set of batteries that power one or more electric motors.
At lower speeds, say when the car is traveling through town, the electric motors can work alone to drive the wheels, and the internal combustion engine switches off. But it turns on again if the driver needs a sudden burst of acceleration or the car exceeds a certain speed.
Under these circumstances the electric motor works in tandem with the conventional engine. The electric-only range of these hybrids is limited to only a few miles.
Once the batteries are depleted they need to be charged via the engine and brake regeneration - something the car does automatically.
Plug-in hybrids (examples are the Toyota Prius Plug-In, and Hyundai Ioniq) have a greater electric range because they have larger capacity batteries and allow the owner to top up the batteries via an electric outlet when not driving.
The bigger battery allows them to run on electric power for extended periods, sometimes even at freeway speeds, and the brakes are still used for recharging.
Straddling the line between pure electric cars and hybrids are cars equipped with "range extender" engines. Range extenders (an example is the BMW i3 Range Extender) also have a conventional engine and batteries with electric motors, but the difference here is that the engine has no mechanical connection to drive the wheels - it’s only used to charge the batteries, which are also kept topped up via regenerative braking.
For some drivers, switching to a hybrid from a conventional car can take getting used to, due to the lack of a transmission shifting, and the fact that the motor will shut off at random. But after a few days of driving, it becomes easy to relax and just let the computers figure it all out for you.