If you are looking for a backer material that is inexpensive, easy to work with and long-lasting, look no further. Contractors and DIYers love cement boards because:

They hold up to moisture: Although they are not 100% waterproof or moisture-resistant, cement boards hold up to moisture better than drywall. Cement boards are an excellent choice for humid rooms, such as your bathroom, because they are less susceptible to mold, rot and decomposition that naturally occur in moist environments..

They add stability: Because they are constructed and dried offsite, cement boards offer a sturdy backing for tile, resulting in fewer cracks and much higher load capacity.

They are easy to install: Cement boards are easy to work with and install. Because they are created offsite, you save time often associated with drywall. This convenience means you can usually finish your project sooner. They are also easy to work with — simply score, cut and place.

You see less shrinkage: When the cement boards are dried at the factory, they undergo all shrinkage or expansion before they are ever shipped out. This means your cement board is stable, and you will not experience any unexpected shifting during or after installation.
In some places, using cement boards is required for certain building projects. Always consult local building codes before purchasing building materials.