mAh is a rating of a battery's capacity. A 4400 mAh battery is capable of delivering 4.4 amps of current for one hour. A 6600 mAh battery is capable of delivering 6.6 amps for one hour. That is not to say that both batteries will only last for one hour, since the laptop will probably draw less current than that. The important thing to notice is that the 6600 mAh battery has 50% more capacity than the 4400 mAh battery. If battery life is your #1 priority, the larger battery would be a good choice. However, it may be larger and heavier than the 4400 mAh battery. If a small, lightweight laptop is #1 priority, the smaller battery might be better. Also, if the laptop will not be unplugged, on the go all the time, the smaller battery might be a better choice due to it being cheaper. As all things engineering, there are compromises to be made.
The difference is an increased battery capacity (hence longer runtime). A batteries capacity is measured in Ah (or mAh) and is the product (ie multiplied together) of the current being drawn and the time the current is drawn for. Thus a 4800 mAh battery can supply a 2A current for 2.4 hours (ie 4800/2000) while a 4400 mAh battery can only supply a 2A current for 2.2 hours.
the fundamental difference between a battery and a generator is that a battery uses chemicals
4400 mAh means that the battery can produce 4400 mA for one hour. Similarly, 7200 mAh means 7200 mA for one hour. In reality, these specifications are for a eight-hour rating, meaning that the 4400 mAh battery can produce 550 mA for eight hours but, comparatively, you can just ratio the ratings, so the 7200 mAh battery will last 60% longer than the 4400 mAh battery There's more to it than that, however, as you need to know that the laptop is designed to use either battery, otherwise the camparison is meaningless.
What is the difference between cylindrical and prismatic battery cells?
There is no difference between lead acid accumulator and lead acid battery.
a vented battery is vented and the regular battery is regular
There is no difference between an alkaline battery and a pile alkaline battery. "Pile" is just a term used in French to refer to a battery. Both terms describe the same type of battery that uses an alkaline electrolyte.
no difference, except price.
Assault is the threat of harm. Battery is the act of inflicting harm
It is a battery.
Potential difference (voltage)
the difference between lightning and a single cell battery