Imagine that you're playing a game of tag with your friends. Now, let's say that instead of only trying to tag the person who is "it," you start tagging everyone you see, even if they aren't playing the game. That would be an indiscriminate attack - you're not targeting one specific person, but instead, anyone who happens to be nearby.
In the context of war or conflicts, an indiscriminate attack is when a group or individual uses weapons or methods that harm or kill people who are not directly involved in the conflict, such as innocent civilians, medical workers, or children. It's like throwing a bunch of rocks into a crowd, without caring who gets hit.
Indiscriminate attacks are generally frowned upon and sometimes illegal because they cause harm to innocent people who are not involved in the conflict. It's important to try and minimize harm to people who are not directly involved in the conflict, so they can go about their daily lives without fear of getting hurt.