Travel, Journey, Trip and Voyage

Travel

Travel means ‘traveling in general’.

I am interested in travel. (= I am interested in traveling in general.)

Travel is usually uncountable. It is sometimes used in the plural and then it means a long tour in which several places are visited.

Who is the author of ‘Travels with a Donkey’?
I have met many interesting people on my travels.
Is he back from his travels yet?

To travel is to make long journeys.

Light travels faster than sound.

Journey

Journey is usually countable. A journey is one piece of traveling.

Wish you a good journey. (NOT Wish you a good travel.)

Trip

A trip is a return journey. It also refers to the activity which is the reason for the journey.

He is on a business trip.

Compare:

Did you have a good journey? ‘No, the train broke down.’
How was your trip? ‘Successful.’

The noun trip is not usually used to refer to expeditions which have a very serious purpose or which take a long time.

Amundsen made his path-breaking journey to the South Pole in 1911. (More natural than ‘Amundsen made his path-breaking trip to the South Pole in 1911.)

A voyage is a long sea journey.