In 1982, some people in Spain wanted to take control of the government by force. They thought that the way the government was running things was not good and they wanted to change it. They planned to do this by capturing important buildings and people, like the king and the prime minister. This is called a coup d'état.
But, the Spanish government was prepared for this and were able to stop the people who were trying to do the coup. They arrested many of them and the government stayed the way it was.
It's not okay to take power by force. In Spain, the government is chosen by the people who vote in elections. If people don't like what the government is doing, they can speak up and try to change things in a peaceful way.