When people make music, they use different notes to make a song. Some notes sound more important than others, kind of like how some words in a sentence are more important than others. The note that sounds the most important is called the "tonic" note.
Now, imagine playing a game where you're trying to find your way home. You might want to stop and rest at different places before you get there. In music, there are some notes that sound like they're resting spots, or "resting tones." The most important resting tone is called the "dominant" note.
The dominant note is like a "musical signpost" that tells you where you are in the music. When a song has a dominant note, it makes you feel like you're moving forward towards the end of the song. It's kind of like when you're playing a game and you see a sign that says "Home is this way!" - it gives you a sense of direction and purpose.
So, in summary, the dominant note is a really important note in music that helps guide the listener and gives a sense of direction and purpose to the song.