Difference between STIs and STDs

What is the difference between STIs and STDs? 

Sexually transmitted infections (STIs) and sexually transmitted diseases (STDs) are words  often used interchangeably.

The primary difference between them is; STIs present without symptoms (asymptomatic), you can have a sexually transmitted infection without showing any symptoms. While STDs present with symptoms.

Because majority of sexually transmitted conditions are without symptoms, experts prefer using STI instead of STD so as to continuously improve accuracy, and also reduce stigma.

While some STIs develop into STDs, some don't, an example is human papillomas virus (HPV). It usually clears on it on without leading to serious health problem. But when it doesn't clear on it on, and result to another condition then it becomes a disease.