Homemade: this can be either a cloth mask with a high thread count or a cloth mask with more than one layer.
Carbon: masks that feature carbon filters help purify the air around you, keeping dust, mold, and chemicals at bay.
HEPA: some masks may have individual HEPA filter cartridges inserted in them, which can add another layer of protection. But be on the lookout for proper labeling and be aware that some products may instead be labeled as HEPA-type or HEPA-like, which means they are not authentic HEPA filters.