The little I know about Web 2.0! Task #4

People explaining Web 2.0 appear to like to use a number of acronyms, such as RIA (rich internet applications) and SOA (service oriented architecture). They also like to bandy around 'words' such as 'tagging', 'mash-up' and 'ajax'. I am hoping that as I delve deeper into this course that this terminology will become clearer! My understanding so far seems to be that the applications available are only viable if and how people use them.