Portuguese-speaking African countries are countries in Africa where the official language (the language that they use for communication) is Portuguese. There are six of them: Angola, Mozambique, Guinea-Bissau, Cape Verde, São Tomé and Príncipe, and Equatorial Guinea.
These countries used to be colonies of Portugal, which means that Portugal used to control and rule over them. During this time, Portugal taught people in these countries how to speak Portuguese and made it the official language.
Now, even though these countries are independent (which means they are not controlled by Portugal anymore), Portuguese is still the official language in these countries, and many people there speak it as their first language.
Each of these countries has their own unique culture and traditions, but they all share the same language. Knowing Portuguese helps people from these countries communicate with each other and with people in Portugal, Brazil, and other countries where Portuguese is spoken.