Plug-in hybrids are similar to mild-hybrid vehicles in that they switch between using the diesel/petrol engine and electric motor to improve efficiency. The difference is, unlike regular hybrids, plug-ins come with a higher-capacity battery and can be plugged-in to drive short distances on all-electric power. So, if you regularly make short trips and very rarely go on long adventures, this is a great way to keep your on-road activity free from fuel consumption.
Plug-in hybrids are the ultimate form of hybrid models, because, as you might have gathered, you can plug them into an external source of electricity to charge the batteries. This is great, because you can top the batteries up overnight and have a full charge when you head to work the next morning (or even at public fast chargers). This means you can maximise the electric-only range, and if your daily commute is quite short, you might find yourself rarely calling on petrol power, saving you lots of money in the long run.
If you don’t want to plug-in the hybrid you don’t have to. It will simply function as a regular hybrid. However, the downsides are that the charging technology tends to make PHEVs pricier than other hybrids. Meanwhile, if you have no means to charge the battery yourself, you might as well save that initial cash and go for a normal hybrid.