Explain size and structural differences with measurements?

Bacterial cells are microscopic, typically 0.5–5 micrometers (µm) in size, while onion cells are much larger, around 100–400 µm long. Structurally, bacteria are prokaryotic, meaning they lack a true nucleus and membrane-bound organelles. Their DNA floats freely in a region called the nucleoid. Onion cells are eukaryotic, containing a nucleus, mitochondria, vacuoles, and chloroplasts. Bacteria have a simple cell structure with a plasma membrane, cell wall, and sometimes flagella or pili for movement. Onion cells have a thick cellulose wall, large central vacuole for water storage, and clearly visible cell boundaries under a microscope. The size difference is vast: dozens of bacteria could fit inside one onion cell. This reflects their functional differences bacteria perform all life processes within a single compartment, while onion cells are specialized units in a multicellular organism.