Per the CDC
What are STDs? Sexually transmitted diseases (STDs), also known as sexually transmitted infections (STIs), are very common. Millions of new infections occur every year in the United States.
STDs pass from one person to another through vaginal, oral, and anal sex. They also can spread through intimate physical contact like heavy petting, though this is not very common.
STDs don’t always cause symptoms or may only cause mild symptoms. Therefore, it is possible to have an infection and not know it. That is why getting an STD test is important if you are having sex. If you receive a positive STD diagnosis, know that all are treatable with medicine and some are curable entirely.
There are dozens of STDs. Some STDs, such as syphilis, gonorrhea, and chlamydia, are spread mainly by sexual contact. Other diseases, including Zika, Ebola, and mpox, can be spread sexually but are more often spread through ways other than sex.
STDs are preventable. If you have sex, know how to protect yourself and your sex partner(s) from STDs.
Learn more at: CDC - STD Diseases & Related Conditions