STD stands for sexually transmitted disease. STI stands for sexually transmitted infection. Often the terms are used interchangeably and the truth is when people are talking about them most of the time they're talking about the same thing. One of the things we know about STDs and STIs is that there is a lot of stigma associated with being diagnosed with one or concern about being diagnosed with one. And putting the term disease on something that is really an infection adds a little bit of stigma to it. And so over time people who are sexuality educators or who work in family planning have taken on using the using sexually transmitted infection rather than sexually transmitted disease 'cause for the most part what you're talking about are bacterial infections, viral infections, parasitic infections, or protozoan infections. For the most part when you're diagnosing someone you're diagnosing them with an infection and either that infection is treatable or curable. It's not necessarily a disease. And so that's just the terminology rationalization about why people might use STI or versus STD but for the most part we're talking about the same thing.