幂（power）是指数运算的结果。当m为正整数时，nᵐ指该式意义为m个n相乘。当m为小数时，m可以写成a/b(其中a、b为整数），nᵐ表示nᵃ再开b次根号。  把nᵐ看作乘方的结果，叫做n的m次幂，也叫n的m次方。

数学中的“幂”，是“幂”这个字面意思的引申，“幂”原指盖东西的布巾，数学中“幂”是乘方的结果，而乘方的表示是通过在一个数字上加上标的形式来实现的，故这就像在一个数上“盖上了一头巾”，在现实中盖头巾又有升级的意思，所以把乘方叫做幂正好契合了数学中指数级数快速增长含义，形式上也很契合，所以叫做幂。

大巾谓之幂。——《小尔雅·广诂》

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The power of a number says how many times to use the number in a multiplication. Powers are also called Exponents or Indices. For example, 8^2 could be called “8 to the power 2” or “8 to the second power”, or simply “8 squared”. 

Some interesting fact about Power : 
 

1.    If the indices is 1, then you just have the number itself. For example, 5^1 = 5

2.    If the indices is 0, then you get 1. For example, 5^0 = 1

3.    Exponents make it easier to write and use many multiplications

4.    Negative exponent means how many times to divide one by the number.For example, 5^-1 = 1 /5 = 0.2

https://www.geeksforgeeks.org/power-in-mathematics/