Here's a breakdown:

* Chloroplasts are organelles found in plant cells and some algae. They are responsible for capturing light energy and converting it into chemical energy in the form of glucose.

* Within the chloroplasts, there are stacks of disc-shaped structures called thylakoids. These are the sites of the light-dependent reactions of photosynthesis.

* The space between the thylakoid membranes is called the thylakoid lumen, while the space surrounding the thylakoids is called the stroma. The stroma is where the light-independent reactions of photosynthesis take place.

So, to summarize: Photosynthesis occurs within the chloroplasts, specifically within the thylakoids and stroma.