An observation is when you use your senses to describe something. You describe how something looks, what it sounds like, what it smells like, you might even describe what it tastes like. When you write an observation you are trying to make the person reading it feel like they are in the place, or eating what you are eating!
Here is a sample of an observation about a sour gummy worm.
"I'm not going to eat THAT!" I said. I couldn't believe my friend wanted me to eat a worm! But then I looked closer. I saw that the worm was blue and red. I knew that real worms weren't red and blue, so I looked a little closer. I saw it was covered with sugar! Maybe I would eat this worm! My friend said that the worm was really sour candy - really sour! I thought about the time I ate a really sour lemon, and my mouth started watering! I just couldn't decide if I should eat it! Finally, I decided I could do it. It was just candy. So I put the gummy worm in my mouth! It was so delicious! I can hardly wait to eat another!
Another kind of observation is the kind you would do for a science report. You might have to record the weather in your city for a month, or describe what happens when you mix two paint colors together. Observations are really fun, and also very important.