And these pores or holes within our cell wall basically allow relatively large molecules to actually pass into this region here, which is known as the periplasm. So the periplasm actually contains different types of important enzymes, different types of important hydrolytic enzymes that break down different products that end up within this space. And that helps our bacterial cell actually digest and break down different types of molecules, which then are ingested into our cell. Now, earlier, I mentioned that there are two different types of bacterial cells. So how exactly do we categorize different types of bacterial cell? So, bacterial cells can be categorized based on their structure of the cell envelope.