Water+Dust Resistant : IPXX | What is IP rating?

Now a days many flagship smartphones are having a specific IP rating for water and dust resistant. But do you know actually what is IP? not internet protocol :P . IP means Ingress Protection. The team Electrotechnical Commission who is responsible for certifying international standard for electronic gadgets certified this standard.
 IP XX is what rated on a smartphone. For Ex. IP 68. Here 6 and 8 both are different. The first digit (6) is protection rating of solid particles and the second digit (8) is the rating of liquid protection. This ratings comes from 2 separate charts shown below. Please note that that liquid protection rating doesn't means that it can survive lower ratings such as water jets or any kind of pressure nozzle sprays.

Solid Protection or Dust Protection

0 - No protection.

1 - Protection against objects up to 50mm. Also, protection against any large surface of the body, such as the back of the hand, but no protection against deliberate contact with a body part.

2 - Protection against objects up to 12.5mm, along with fingers or similar objects.

3 - Protection against objects up to 2.5mm, such as thick wires or tools.

4 - Protection against objects up to 1mm, including most wires and screws.

5 - Not entirely protected from dust, but enough to significantly affect performance significant damage.

6 - Totally protected against dust.

Liquid Protection

0 - No protection.

1 - Minimal protection against vertical drops of water, such as very light rain.

2 - Protected by vertical drops of water when the device is tilted at 15° from its normal position.

3 - Protection against sprays of water when the device is tilted at 60° from its usual position, including rain.

4 - Protection from sprays and splashes of water from any direction.

5 - Protection against water sprayed directly from a low-pressure nozzle measuring 6.3mm, from any direction.

6 - Protection from high-powered water jets with a 12.5mm nozzle, from any direction, such as a shower.

7- Protected for up to 1m of immersion for up to 30 minutes, including splashing from a shower or an accidental (and brief) dunking.

8 - Protection against submersion beyond 1 metre. May mean that device is hermetically sealed or merely that any water that can get inside will cause no damage.

PLEASE NOTE THAT ITS WATER RESISTANT. IT DOESN'T MEANS ITS WATERPROOF ANYWAY. IT IS RECOMMENDED TO AVOID WATER AND DUST AS MUCH AS YOU CAN.