How many pairs of legs do all true insects have?

True insects are members of the class Insecta, and one of their defining characteristics is having three pairs of legs. This means that all true insects possess a total of six legs, as each pair consists of two legs. This characteristic differentiates them from other arthropods which may have more or fewer legs, such as arachnids which have eight legs, or crustaceans which can vary widely in leg count.

Understanding this fundamental aspect of insect morphology helps in the identification and classification of insects, as leg count is a key trait that distinguishes them within the animal kingdom. Thus, the correct answer accurately reflects this essential biological fact about true insects.