Ford Prefect is Arthur Dent's friend. He rescued Dent when the Earth is unexpectedly demolished to make way for a hyperspace bypass at the start of the story.
Although his heart is in the right place and he is shown to be highly intelligent, resourceful, and even brave, Ford is essentially a dilettante when it comes to causes such as the search for the question to the ultimate answer of "life, the universe, and everything."
Ford takes a more existential view of the universe, sometimes bordering on joyful nihilism. He is eccentric and broad-minded – no doubt due to his vast experience of roughing it around the galaxy – and has an off-key and often very dark sense of humour.
Source: https://en.wikipedia.org/wiki/List_of_The_Hitchhiker%27s_Guide_to_the_Galaxy_characters