Condensation occurs when water evaporates from liquid form and is then deposited on a surface.
This process occurs when there is a small space between two substances, such as the top and the bottom of an aluminum can. When air from outside enters this space, the water vapour molecules condense on the cooler metal can. The condensed liquid inside evaporates again and leaves more liquid for the air to evaporate. This cycle of evaporation and condensation continues.
Condensation in basements is often the result of seal failures, which happens when there are gaps in your house’s foundation or walls. Water can enter your basement when you have a leaking roof or chimney and through cracks in the concrete foundation and floor systems.
You can’t fight condensation, it’s a natural law of physics, that’s just how water acts. You can, however, get rid of water in your basement, so it can condensate somewhere else, where it won’t damage your basement structure and your belongings. That’s what waterproofing, both exterior and interior, are supposed to do (and what they actually do if the system is properly installed by professionals).