What is the meaning of alternating blue colored curbstones?

1. To indicate and emphasize sidewalks and built traffic islands.
2. Correct answer: Parking space for vehicles according to conditions laid down by the local authority . usually for payment.
3. No parking or stopping besides the curbstones, except for taxis on an urban road.
4. Arranged parking space for public vehicles only.

WhyA blue-and-white curb is parking under the rules of the local authority, usually paid. How to pay and the hours are on plates nearby. Black-and-white just highlights the sidewalk; red-and-yellow is where public transport stops.