British English vs American English

I was very busy yesterday, because I took on an assignment which had to be finished quickly. I could have finished and delivered it at the specified time. Though the assignment was just to translate English to Japanese, there was a problem. My client gave me a document file (UK version) to translate while providing a reference file (US version). Wow! As there are some differences between British and American English, I thought I was assigned a formidable task. I queried the client about that problem, so he replied, "Though British vocabulary is difficult to translate to Japanese, you need to translate referring not to British but to American English." The problem was solved and I finished the translation from American English to Japanese. Afer sending it, I looked at the two files and it was beneficial for me to verify British and American English.

American and British English are the two varieties of English most widely used. Generally, it is agreed that no one version is "correct," however there are certainly preferences. I have listed some of the differences below:
1. Vocabulary and spelling
2. Use of prepositions and past participles

As I like British English, I am studying British English. I'd like to improve writing and reading skills. I think that reading books from Britain carefully to understand their style of writing is very beneficial. Additionally, I can visit websites or watch movies that use British English. This is one of the best ways of improving one's language skills.