You'll find it easier to get meaningful answers on this site if you phrase your posts as questions. It can also help to know why a question being asked. e.g. the best response here might be different when offered to a student taking GCSE Economics (where a 'broad brush' answer would probably suffice) to one required by someone studying at degree level (where far more detail could be needed).
However, to get you started, take a look at this document from the OECD:
http://www.oecd.org/tax/public-finance/Debt-and-macroeconomic-stability.pdf
If you need more help, please post again.