This course presents the general guidelines for using short fibers in concrete and reviews the historical aspects. When concrete is loaded in tension, short fibers stretch and carry some stresses due to tensile forces. Once the concrete cracks, these fibers do not necessarily fail. Instead, they bridge the tensile (or flexural) cracks and start to carry more stress. The closer the fibers are to a small crack, the sooner they can stop it from growing uncontrollably. That is why concrete with large fiber content increases the chance of fibers bridging the cracks on their incipient formation. Stage 1 of cracking is when cracks begin to form in the cement matrix. This eLearning course, Fiber-Reinforced Concrete: Introduction and Production, is available online at www.ACIeLearning.org. Additional courses on this topic include: Testing and Design and Applications.