@TheJohnWood [THE before a proper noun]

In British English, we don't often use the definite 'the' article before a proper noun, except in a few cases:

When we are talking about a person with famous name:

I had a drink with Paul McCartney last week.
What, THE Paul McCartney? The former member of the Beatles?
No, he's a builder from Croydon.
(THE is said with emphasis, and always pronounced "thee".

When we wish to distinguish a person from others with the same name, e.g. when talking to someone who knows them both:

I talked to John Smith yesterday. He's the John Smith who has a kebab shop, not the John Smith who drives a taxi.

When taking about a ship:

I sailed on the Queen Mary.

Website names are, however, not subject to the rules of grammar, and probably thejohnwood was chosen because johnwood was already taken.