A net (sometimes written nett) value is the resultant amount after accounting for the sum or difference of two or more variables.
In economics, it is frequently used to imply the remaining value after accounting for a specific, commonly understood deduction.
Similarly, an individual's net worth is the difference between their assets (what they own) and their liabilities (what they owe to others).
The word net, in this sense, originally derives from the Latin nitere (to shine) and nitidus (elegant, trim), and more recently from the French net (sharp, neat, clean).
[1] In this sense, it may appear, separated by a comma, following the noun it modifies, e.g., "earned two million dollars, net".