Chloroplasts are only found in the plant cell. They collect light energy from the Sun and are able to convert it into chemical energy through a process called photosynthesis. Chloroplasts have a chemical in them called chlorophyll. It is this chemical that gives the plant its green color. There are many chloroplasts in a single plant cell, as is shown by the picture.
Chloroplasts are a lens shaped organelle. They contain three main structures. These are the thylakoids, grana, and stroma. Thylakoids look like a single coin These are stacked on top of one another to form the grana, or a single granum. Outside of this is the stroma, a fluid that separates the grana. All of this is surrounded by two mebranes with a very thin space between them.
This is a real picture of a single chloroplast. Here you can see the lens like shape of the chloroplast. The long, dark structures are the grana. If you look close enough you can make out the singular thylakoids. Outside all of this is the fluid called stroma. This is the organelle that turns light energy into chemical energy.
Pictures taken from "Biology" by Neil Campbell