How does the financial crisis in america affect the uk and other countries?

PLEASE EXPLAIN in really dumed down language as im yet to understand whats really going on thankyouHow does the financial crisis in america affect the uk and other countries?
Basically the USA is a superpower. There are lots of 'global giants' over there, which means big money. If they start going down the drain/failing, then people tend to lose faith in the market and start to put less money in. Eventually things start ending up costing less overall - their value decreases. Some companies are international, so this also affects other countries. The USA also gives out lots of loans to countries, which will affect other countries more if they start calling those loans back in quicker.