Baby sizes typically refer to the clothing and diaper sizes designed for infants and toddlers. These sizes are often categorized by age, weight, and height, with common labels such as Newborn, 0-3 months, 3-6 months, and so on. Each size is tailored to fit the average measurements of babies at different developmental stages, ensuring comfort and ease of movement. When shopping for baby clothes, it's important to consider that sizes can vary between brands. Some may run larger or smaller than others, so checking the specific size chart provided by the manufacturer can help parents choose the right fit for their little one.