Definition of Hub City

What does the term "hub city" mean as it applies to the NHL and their 2019-20 season? What is a "hub city"?

Part of the NHL's plans to restart their 2019-20 season was the usage of two "hub cities".

These two cities would host ALL of the league's playoff games. One Conference would play in one city, and another Conference would play in another.

These two cities would host all of the players, personnel, coaches, etc., as well as all of the playoff games.

The two cities ended up being EDMONTON and TORONTO.

There were 12 cities that were apparently up for consideration, of which most were located in the United States.

Canada has done a much better job in containing Coronavirus, so the NHL decided to place both hub cities in Canada.

Edmonton will host the Western Conference games, while Toronto will host the Eastern Conference games.

The Stanley Cup final will reportedly be played in Edmonton.