As you search websites on the internet you will find that Fermi's Paradox has basically the following meaning.
It is feasible to conclude there are between 40 and 80 billion inhabitable planets in our galaxy. Ethan Siegel (https://medium.com/starts-with-a-bang/how-many-habitable-planets-are-in-our-galaxy-5bcf6db80 c7f) gives a strong, logical argument for these numbers. So, the paradox basically states: if there are this many planets throughout the Galaxy with this many possible highly technological societies, then why have none of the civilizations on Earth been contacted by one or more of them? In other words the paradox is based on the number of planets being astronomically large, and yet the contact is zero. Some of the websites like to use the expression: "Where are the aliens?"
"Fermi's paradox is the apparent contradiction between the high probability of the existence of extraterrestrial civilizations and the lack of contact with such civilizations." www.femisparadox.com.