I have mixed up these concepts and terminology myself on many occasions, at least when talking about them, even if in my mind I know the difference. I know other people do and just came across it in a question and comments here.
Let me explain.
A visa grants you one or more entries until a certain date when the visa expires.
Each entry you are granted under a particular visa will be for a certain number of days or until a certain date.
People often mistakenly refer to situation number 2. as "my visa is expiring". At best this is ambiguous, but there's not an obvious common way most people know to express it, especially when they're not fully aware that it's wrong.
Under the rules of some visas in some countries you may be allowed to enter a country on the last day the visa is valid, but you can still stay for the usual length of stay even if the visa itself has expired.
On a multiple entry visa you are allowed between two and unlimited stays, each of which will probably have a time limit such as 30 days or 90 days, even though the visa itself may be valid for between six months and ten years, etc.
What is the best concise and clear terminology to differentiate situation 2. from situation 1.? (What wording is used in each English-speaking country in their official documents?)