It all depends on size of meteorite here. If small, not much will happen but if a huge one hit, it could be like a megaton nuclear bomb going off, causing wide spread damage and leaving a crater like the one that is a mile wide in Arizona.
What happens when a meteorite hits the earth?
It make's a crater
There can be lots of potential outcomes if a meteorite hits earth, ranging from a bit of splash in the ocean to the complete destruction of a city (in theory). It all depends on the size of the meteorite, and where it hits.
They range in size between a particle of dust and the size of a football field (or even larger).
They fall to earth when they are captured by earth's gravitational force, which makes them travel at more than 11 kilometres a second. As they reach the denser atmosphere sounding earth they begin to slow down, but are still capable of causing extensive damage.
Recent meteorite damage
In September 2014 a meteorite landed in Nicaragua, leaving a giant crater in the ground; over 12m wide and 5m deep. Luckily this meteorite landed in a wooded area and nobody was hurt, but in 2013 a large meteorite exploded over a populated area of central Russia, injuring over 1,000 people.
Check out this amazing footage here:
Of course, there is no such thing as "a meteorite". There are such things as meteors. Meteorite describes the material that makes them up, and has, thanks to bad popular science, become "another word for meteor" in most people's understanding. Otherwise, the other answers are correct. The meteor that hit Manson, Iowa 75 million years ago was around 2km in diameter. There is almost no trace of it's existence now, and no evidence that it caused a single extinction. 10 million years after that, something (probably a comet) 10km across hit the Yucatan in Mexico and put an end to a lot of life on Earth (including (probably) the dinosaurs).
