Fet and de las jons are two political terms used in Spain that are connected to some historical and political events that happened in the early 20th century.
Imagine that you and your friends are playing a game and some of your friends want to have more power and control over the game. This is kind of what happened in Spain in the early 20th century. Some people wanted more power and control over the country, so they formed two groups with different ideas on how to achieve this.
Fet (also known as the Falange Española Tradicionalista y de las Juntas de Ofensiva Nacional Sindicalista) was a political party that believed in having a strong and authoritarian government that controlled everything. They wanted to create a new order in the country without democracy, where only one party would have control over everything. They thought that Spain needed a strong leader who would make all the important decisions instead of having everyone vote for their representatives.
On the other hand, the de las jons (also called Juntas de Ofensiva Nacional Revolucionaria) were a group of people who fought for a more democratic government, where people could vote for their representatives and have a say in how things were run in the country. They believed in the right of workers to have a fair wage and safe working conditions. They wanted to create a society that was more equal and fair for everyone.
So, to summarize, fet was a political party that believed in a strong and authoritarian government, while de las jons fought for a more democratic and equal society.