@kensuke ty for the help!!

Both www and 笑 or 笑笑 have the same meaning. I normally use 笑 since it can be understood by pretty much all generations. www tends to be used as an internet slang, so is used by younger generations. Some young ones do prefer to use www because it is easier to type and stuff, but some people might not understand what it is :) Bottom line, you can use your favorite one.笑