Differences between an ape and a monkey

I took my toddler to the Singapore Zoo recently and overheard a child asking his mother, "Mum, what is the difference between an ape and a monkey?" This is a commonly asked question. Here's a brief answer:

The main difference between an ape and a monkey is that an ape does not have a tail while a monkey has a tail.

There are other differences between an ape an a monkey. They are:
(1) An ape is generally larger than a monkey.
(2) An ape has a longer lifespan than a monkey.
(3) An ape has a larger brain-to-body size ratio.
(4) An ape has higher intelligence.

Of course, there are exceptions. Some monkeys do not have tails and some are large. Gibbons, considered to be lesser apes, are smaller than some monkeys.

Great Apes
Gorillas, Chimpanzees, Bonobos and Orang utans

Lesser Apes
Siamangs and Gibbons

Monkeys

Baboons, macaques, tamarins etc

You can find out more by reading these books:
Apes and Monkeys by Barbara Taylor
All about Monkeys and Apes by Jordyn Madison

Here are some pictures of apes and monkeys:

TAMARIN

Gorilla

ORang Utan with babY

Chimpanzee

Gibbon