Difference between two words

Literally, both words have the same meaning. Poisonous animals and venomous animals produce a toxin that is injurious or even lethal to other animal. From the scientific point of view, the difference between the two terms involves how that toxin is delivered to the victim.

A poisonous animal has poison in it. The poison may be harmful if you get it in or on you. But you have to touch or try to eat the dark frog to get the poison.

A venomous animal has poison in it too. The toxin is produced in a gland. But a venomous animal can inject its toxin into another animal through a bite or sting.

Poisonous usually describes an object or food. Life object should use venomous. However its fine to use either one to describe animals.

poisonous is means that eat or drink or touch to cause illness or death
Venomous means that produce poisonous liquid to attack

Words can actually have the same meaning.
That two words, 'poisonous' and 'venomous', are examples.