How these differ from each other

This is the question the category actually raises, and the one the official shop does not answer on a listing page. One line each:

• Hydrate — Orange — Both other variants contain this base entirely. Choose plain for a child, or to avoid doubling up.
• Hydrate — Raspberry — Both other variants contain this base entirely. Choose plain for a child, or to avoid doubling up.
• Hydrate + Hyaluronic Acid — Hydrate + Immune Support: same base, different addition. The brand gives no guidance if you want both.
• Hydrate + Immune Support — Hydrate + Hyaluronic Acid: immune actives instead of HA, on the same base.