LiPO - Lithium Polymer or lithium-ion polymer battery is a rechargeable battery of litium-ion technology using polymer electrolyte instead of liquid electrolyte.

Huh? Can you say that again in English please?

Lithium-ion:

Let's just say that it is rechargeable battery technology that provides a greater charge than nickel metal hydride or NiMH.

Polymer:

A useful chemical made of many repeating units

Electrolyte:

A gel which contains ions and can be decomposed by electrolysis that are present in a battery

So, during a charge, each cell of a lipo battery gets balanced charged.