Final answer:
A reserve is a confirmed portion of a mineral deposit that can be extracted at a profit. It is an aggregate of valuable minerals that can be extracted and used.
Step-by-step explanation:
A reserve is a confirmed portion of a mineral deposit that can be extracted at a profit. It is an aggregate of minerals that have value and can be extracted and used. For example, diamond reserves and other minerals and ores are found in abundance in certain regions and can bring huge profits when sold.