A friend once told me a story of how an interaction with her mother changed her perspective on communication. She said that she had been going through a break up at the time, and was venting to her mother, when her mother responded with "Do you want my advice, or my sympathy?"
Often times, when we have something important to talk about, we consider how we expect the other person to respond, and talk to people who will respond the kind of way we want. We may choose to speak to someone who we know can keep a secret, or who gives good advice, or who will say nothing at all, only listen. Sometimes we may turn to someone who won't want to talk about it at all, and will instead distract us from our problems. This can be great if you have a number of close friends who reliably respond in different ways, and you are able to predict this and make use of it. However, not everyone is in this situation, and so instead, we end up with interactions where people are not getting their desired responses.
Take an interaction between example-humans Alice and Bob. Alice's goal in the conversation may be to be heard, whereas Bob may want to feel validated for what he says. If Alice is talking, Bob may point out something or make a clever remark. Instead of validating Bob, Alice feels like she hasn't been heard, and is quiet in response. Now Bob has not been validated either, and they are both sad.
Sometimes, a person's desired response can be inferred. This is like how generally, if someone tells a joke, their desired response is for you to laugh, or at least acknowledge that the joke was funny. However, this isn't always easy to tell. Some of us may know the best thing for our best friend in a time of stress, but we don't always know what's right for someone else, even if we are close. Often times we will assume that what works for us will work for them, but then there is a risk of emotional damage. Trying to talk about a situation that someone wants to avoid thinking about may exacerbate the problem or cause tension between two people. Usually, it is better to ask a person what they need -- like how my friend's mother asked her.
Going more deeply, some people may tend to have common desired responses, in general interactions. Think of the person constantly telling bad jokes, excited to hear people groan and laugh, or someone who loves giving advice and recommendations. The first of these two may love the validation they get from humor, whereas the second may want to feel helpful, and be appreciated for it. This goes far deeper than a single situational interaction; these people want these kinds of responses in everyday conversations. This may even tie to how we want others to see us (clever or kind) or how we most enjoy interacting with others (playing with ideas or working with people, receiving attention or giving it). A person's desired response may not always be the response that feels right, or the response that we want to give -- and that's perfectly okay. But it does give us insight into what drives them, what is important to them, and who they are as a person.