A condom is a popular and effective method of birth control. It is a latex device which a man wears over his penis while having sexual intercourse with a woman. It can also be used for gay sex between two men, which special condoms are available for. One very big plus with condoms is they protect against disease as well as babies.
Slang terms for condoms include "jonny" and "rubber".
Condoms are not only useful for preventing pregnancy, but they are also effective in preventing the transmitting of Sexually Transmitted Diseases and Infections. Condoms can only be used once, so PLEASE don't try and use the same thing again!
Condoms can be sex toys as well, you can get condoms in different colours, you can get glow in the dark condoms, you can get flavoured condoms to make felatio more peasant, you can get condoms with ridges that please the lady.
Politics and religion
Fundamentalist conservatives generally oppose the use of condoms as they see it as unnatural, while forcing your pregnant teenage daughter to raise a kid she doesn't want is far more acceptable. Instead, they prefer to teach their children about abstinent relationships, in the hope that not educating adolescents about sexual intercourse and methods of birth control will result in them not having sex until they're married. The sex drive is so strong that Pre-marital sex happens and kids who don't understand condoms just do it without them or don't use condoms properly. Unfortunately unprotected sex leads to unwanted pregnancies as well as to the spreading of STDs. Fundamentalist conservatives also oppose the use of condoms inside of marriage, instead proposing a "pull out when you're close" technique, which any man that's tried it will tell you it's just not the same and often fails... Alternativedly Conservatives favour having far too many kids even if you can't look after them properly, see Duggar family.
Liberals generally approve of condom usage as it downsizes the numbers of unwanted pregnancies and abortions, as well as sparing the lives of teenage guys who risk getting murdered by a girlfriend's protective older brother.
Exception: When the couple want a baby and can provide a good home for any child. Then leaving the condom off is OK and very pleasant.
Roman Catholic Church
The Roman Catholic Church opposes condoms used for contraception but may accept condom use to prevent disease. Ordinary Roman Catholics in many parts pf the world disagree with the Church over contraception and use condoms or other contraceptives when they want to enjoy sex without unwanted babies. 
Someone at the Vatican has an unofficial, illegal use for condoms, customs intercepted a parcel with condoms containing liquid cocaine worth €40,000 destined for the Vatican. The intended recipient was likely tipped off and didn't collect the parcel. 
Condoms work about 97% of the time, so it must be noted that they can not be guaranteed to prevent pregnancies always or the transmitting of STDs/STIs. This section is here to prove to fundmantalist conservatives that we do not lie to our audiences about methods of birth control as they do.
What to do if your jonny splits
Emergency Contraception won't stop STD and it's not as effective as regular contraception. Still accidents happen, so you're straight, you've had unprotected sex and you're not ready for a baby yet or you're not ready for another baby yet, what should you do? The Morning After Pill is much better than doing nothing. It's best to take care with condoms and avoid accidents if possible but you should know about the morning after pill just in case.
- Protection Can Be Fun - 10 Most Brilliant and Fun Condom Ads These are hilarious. LOL
- Planned Parenthood on Condoms
- Some condom tips How UK'ers make sex safe and fun