When used consistently, condoms are highly effective in preventing the transmission of HIV and most STDs. Respect yourself and your partner enough to use protection. The most important thing when choosing a condom is to make sure it’s made of latex or polyurethane. Both of these are effective in preventing STDs, HIV and pregnancy.
When choosing a condom, avoid using animal skin (or “natural”) condoms, which prevent pregnancy but aren’t as effective in preventing STDs and HIV.