Hi there Oswin,
I think the answer to your question would be quite different depending on who you ask. For me, love has many meanings. It's too hard for me to pick just one.
The first thing that comes to mind is familial love. Even though my mum died when I was a little girl, the way she told me stories and taught me magic and always took extra good care or me made me feel loved. And dad too. He would do anything for me. I'll also never forget Harry's mum who also showed extreme love when she sacrificed herself for Harry. Or Dobby the house elf who sacrificed himself too. I think that's beautiful.
Secondly, I think of my friends. I didn't know how lovely it was to have good friends until I met Ginny, Hermione, Harry, and Ronald. They made me feel like I belonged. I know we would all protect each other in any situation. I love my friends.
Lastly, I believe that love is a force that can bring peace and drive out darkness. It makes a person feel good and it betters the world. Love is a powerful feeling that can change your whole outlook on life.
I hope you aren't the next Voldemort and that you find love in your life as well.
Have a beautiful, love-filled day!