Human intelligence, or "HUMINT" for short, is basically information that people get by talking to other people. Imagine you want to know what is happening at your school, but you cannot be there yourself. Instead, you might ask your friend who is there to tell you what they see and hear. This is a bit like what intelligence gathering is all about.
Now, some people do this for a living. They are called intelligence officers or agents. They might work for the government or other organizations, and their job is to find out what's going on in certain places, among certain groups of people or in certain situations.
To do this, intelligence officers need to be really good at talking to people and asking the right questions. They might try to befriend someone who has access to the information they need. Or they might pose as someone else to gain access. They might even use secret codes or signals to communicate with other intelligence officers.
Once they get the information, they need to make sure it is accurate and important. They might compare it to what other people have told them, or they might use other sources like satellite images or intercepted communications to back it up.
Finally, they need to decide how to use the information they have gathered. They might pass it on to their bosses who can use it to make important decisions. Or they might act on it themselves, for example by carrying out a secret mission.
In short, intelligence gathering is like being a detective. You need to ask questions and gather information to figure out what is happening, and then use that information to make decisions. It can be a very exciting and important job, but it can also be very dangerous.