Size 2T is a toddler size that is intended for a 2-year-old or 3-year-old child, while 24 months is a baby size that is designed for babies ages 18-24 months. The name "2T" symbolizes the youngest age intended for the garment, and it is for toilet-trained kids, so it has a slimmer silhouette than size 24 months, which has extra room for diapers. The sizing differs between brands, so it is essential to check the size chart for each brand before purchasing. In general, 2T clothes are longer than 24 months clothes, and they have a distinct "big kid" style. Therefore, 2T clothes are not the same as 24 months clothes, and they are designed for different age ranges and body types.