What do you mean by the term free riding?

The term free riding refers to the situation where people doesn’t pay for the services or product and use it conventially. For example in indian railways there are a huge amount of people who doesn’t take tickets for their journey and this makes huge loss to the railways. Hence free riding could cause a imense loss in the economic market of the country if huge amount of people do the same thing.
The free rider problem is the burden on a shared resource that is created by its use or overuse by people who aren’t paying their fair share for it or aren’t paying anything at all.