Answer: Population , Sample
Explanation:
In statistics, Population can be defined as the overall pool from which a statistical sample is drawn. A population may refer to an entire group of people, objects, events, hotel visits, measurements etc. While a sample is defined as a small part of a population used for statistical analysis, which is intended to show what the whole population is like.
In the case above,the population is the 7000 students in the school while the sample is the 1000 students surveyed.