They provide just about the same protection against pregnancy and also give some protection against STDs, although they break and slip more often than latex condoms. Lambskin condoms, or natural condoms, are effective against pregnancy, but not effective in the prevention of sexually transmitted diseases. It's up to you if you use lubricated or unlubricated condoms, although most teens prefer lubricated. It's obvious that the male condom is most effective against pregnancy when it is used all the time and always used correctly. When used all of the time and when used correctly, condoms are very good at preventing pregnancy.
Most condom failures are because of improper use.
The answer to this question partly depends on which type of condom used. Latex condoms provide excellent protection against some STDs. Polyurethane condoms provide some protection against STDs, although it is still not clear just how much. Remember, lambskin condoms, or natural condoms, don't protect against STDs. The pores are too large to protect against the small particles that cause some STDs.