The decision to select the most needed thing and give up the other thing which is less important is called an economic choice. For example, on a hot summer day, Ahmed went to a tuck shop. He wanted to buy a packet of potato chips well as a pack of juice. Each cost Rs 30. He had only Rs 30. He had to decide which item he needed the most. So, he bought only a pack of juice as it was hot outside. It was his economic choice.
Economics is the branch of social science that deals with the production and distribution and consumption of goods and services and their management,
(used with a singular verb) the science that deals with the production, distribution, and consumption of goods and services, or the material welfare of humankind. 2. (used with a plural verb) financial considerations; economically significant aspects: What are the economics of such a project?
Just to add to your knowledge: The word economics comes from a greek word Oikou-Nomos or O'konomia
The definition of the word economics is "the branch of knowledge concerned with the production, consumption, and transfer of wealth."