What would a false negative and a false positive mean on an std screen test?

See below: False negative & false positive results are testing errors (meaning the test results were wrong). In this case... A "false negative" result means that despite the test being negative, the person actually does have the infection. A "false positive" result means that a positive test result occurred in someone who really did not have the infection.

See below in details: A false negative occurs when the test is red as negative but the condition is present. He false positive occurs when the test is red as positive but the condition is not present. Almost all tests performed will have a percentage of false-negative and false positive readings.