There are so many options available to use as the reinforcement with concrete. Even though some properties of the steel which are compatible with concrete made the choice as steel over other materials. The thermal coefficient of the steel and concrete are similar. Also, it does not need any special tie up during the placement of concrete as it will not float over the concrete. Easy fabrication, recyclable and better bendability at site without detrimental effects in the section are made it as a choice over other materials.
On the other hands, the corrosive nature and expense of the steel are some disadvantages of the steel. The surface of the steel is deformed (ribs) to have a better bonding surface with the concrete.
This is the best than any other.