The difference between a 'bracket' and a 'parentheses' can be a bit confusing. Generally, 'parentheses' refers to round brackets ( ) and 'brackets' to square brackets [ ]. However, we are more and more used to hearing these referred to simply as 'round brackets' or 'square brackets'.
Usually we use square brackets - [ ] - for special purposes such as in technical manuals. Round brackets - ( ) - are used in a similar way to commas when we want to add further explanation, an afterthought, or comment that is to do with our main line of thought but distinct from it. Many grammarians feel that the parentheses can, in fact, be replaced by commas in nearly all cases.
- The government's education report (April 2005) shows that the level of literacy is rising in nearly all areas.
- I visited Kathmandu (which was full of tourists) on my way to the Himalayas for a trekking expedition.
- You can eat almost anything while travelling in Asia if you are careful to observe simple rules (avoiding unboiled or unbottled water is one of the main rules to be aware of.)