Economics is a science which basically studies the use of resources. The word can also refer to a set of principles and rules that tell you how to allocate resources properly.

You can try to memorise this term by learning some popular collocations and answering the contextual questions:

• You can study economics in university as a student. Did you study economics in your university?
• You can also teach economics as a university professor. Do you believe that economics is taught correctly in universities?

Economy, on the other hand, is the economic state of a certain country, region or area, as well as the world economy.

If you open a Wikipedia page of any world's country, you will see the following sections: History, Geography, Economy, etc. Do you understand why?

Since 'economy' refers to a 'state' or a 'condition' of a country/region, it can be an object of some actions, usually performed by governments or other institutions, for example:

• The government can stimulate the economy by attracting foreign investments.
• The government can stabilise the economy.

We can also describe economies of different countries with lots of adjectives, such as 'agricultural economy', 'competitive economy', etc.

Check out this great article for more detailed information: https://keydifferences.com/difference-between-economics-and-economy.html