Babies wear diapers because they cannot get to the toilet, use the toilet and cannot hold their pee or poop in.
If a baby did not wear diapers then they would have pee all over their clothes and poop all over their clothes which would be really messy.
The diaper absorbs the pee and catches the poop and contains it to keep the babies clothes and bedding dry until they can be changed.
Toddlers wear diapers as well when they are not potty trained so they don't pee in their pants or have poop or pee running down their legs.
Then when they are ready to be potty trained they can go without wearing a diaper once they can hold their pee or poop in and make it to the toilet.
Some kids wear diapers until 2 years old and some wear diapers until 3 and 4 years old.
Disposable diapers first came out in 1948 but the disposable diapers didn't see widespread use until around 1970 or so.
In the early days of disposable diapers they were not very absorbent and had to be pinned on and they tended to leak more than the disposable diapers of today.
When disposable diapers first came out they actually were all plain white with no prints.
It wasn't until around 1980's when disposable diapers got much better and started having some form of print on the landing strip of the diaper.
Then around the year 1999 to 2000 is when disposable diapers went from all plastic backed taped on diapers to cloth backed diapers with Velcro tabs.
But still the disposable diapers have plastic underneath them and they don't really breathe any better than the old thicker plastic backed diapers did.
Diapers are called diapers because diaper means a type of cloth that was worn to catch pee and poop in the older diapers.
The word diaper originates to English from Greek diaspros (from dia 'across' + aspros 'white') to medieval Latin diasprum, to Old French diapre.
In the UK diapers are called nappies which is a napkin that was worn to keep the baby protected from peeing on their clothes or pooping on their clothes.
The word diaper was also the term for a pattern of repeated, rhombic shapes, and later came to describe white cotton or linen fabric with this pattern.
Cloth diapers were most commonly used before the invention of disposable diapers and the cloth diapers required a lot of work.
Then in 1948 Johnson & Johnson introduces first mass-marketed disposable diaper in the U.S.
Then in 1961 Procter & Gamble unveiled Pampers. In 1970: American babies go through 350,000 tons of disposable diapers, making up 0.3% of U.S. municipal waste.
Disposable diapers keep the baby much drier and prevent diaper rash and so disposable diapers while they cost money they are worth it.