Beams and columns are crucial in construction for load transfer and stability. Beams transfer loads horizontally, while columns do so vertically. Materials for beams include steel, reinforced concrete, wood, and masonry, while columns are commonly made of steel, reinforced concrete, or composites. They come in various standard shapes and sizes like circular, rectangular, I-section, C-section, and T-section. Precast concrete beams and columns offer advantages such as fast construction, versatility, strength, fire resistance, and durability.