Thread count refers to the number of threads per square inch of fabric, while fabric refers to the type of material the bed sheets are made of. Thread count is important because it determines the quality, softness, and durability of the bed sheets, while fabric is important because it affects the look, feel, and life of the sheets. Depending on your needs, you can select either high quality, low thread count sheets made of luxurious fabrics or low quality, high thread count sheets made of less expensive materials.