Simplify the following text for a Grade 13 native English-speaking person.
Original: While in the past , these illnesses have mostly been referred to as STDs or VD , in recent years the term sexually transmitted infections ( STIs ) has been preferred , as it has a broader range of meaning ; a person may be infected , and may potentially infect others , without showing signs of disease .
Simplified: STDs can also be called sexually transmitted infections ( STIs ) , or venereal diseases ( VD ) .