So, you know how some people decide to become nuns or monks and live in a special place to pray and do good things for others? Well, there are also some people who want to do good things for others but they don't want to live in a special place only for that. These people are part of something called a secular institute.
Now, when you're part of a secular institute, you still believe in God and want to do things to help others, but you can live your normal life, like going to work or school or being with your family. You just try to do good things as much as you can, like helping the poor or being nice to others.
To join a secular institute, you have to go through some special training and make promises to try to live a good life and help others. You might meet with other people in the secular institute to talk about how you can do more good things together.
Overall, being part of a secular institute is a way for people who want to help others and believe in God to do good things while still living their normal lives.