There are 4 types of detergents based on their electrical charge:

• Anionic detergents – Anionic detergents have a net negative electrical charge. This is because of the negatively-charged sulfate groups in the hydrophilic head.
• Cationic detergents – Cationic detergents have a net positive electrical charge. This is because of the positively-charged ammonium group in the hydrophilic head.
• Non-ionic detergents – Non-ionic detergents contain an uncharged hydrophilic group.
• Zwitterionic detergents – Zwitterionic detergents have equal numbers of positive and negative charges, so their net charge is zero.