Modular building is kind of like playing with building blocks, but instead of building a tower or a castle with regular blocks, we build entire buildings like houses, offices or schools.
The way it works is that we take big parts of a building, like a room or a section of a wall, and we build them in a factory. Then we transport them to the site where the building is going to be put up, and put them together like a puzzle.
It's like making a Lego kit where all the pieces are already made for you, so all you have to do is put them together.
What's cool about this is that it's a lot faster than building a building from scratch, because we don't have to make all the pieces on the site like we usually do. It's also less messy and noisy, because most of the work is done in the factory.
Modular building can be cheaper too, because it's easier to control the costs in the factory than on the site. And because there are fewer surprises or mistakes, we can make better predictions of how much we are going to need to spend.
It's like playing with building blocks, but for grown-ups, and instead of a tower, we build entire buildings!