In right hand rule 1, applied to a positive moving charge, what do the thumb and the fingers stand for?

1. Right hand rule 1 gives the direction of the magnetic force on a positive moving charge. 2. The thumb points along the velocity v, and the fingers point along the magnetic field B. 3. A perpendicular to the palm then points along the force F, which is the direction you would push with your palm. 4. One way to remember it is that there is one velocity, so the thumb carries it, while there are many field lines, so the fingers carry them. 5. Putting the force on the thumb reverses the roles and gives a wrong direction every time. _Source: OpenStax College Physics (CC BY 4.0), Ch 22 "Magnetism", section 22.4 Magnetic Field Strength: Force on a Moving Charge in a Magnetic Field_