DEFINITION of 'Standard Error'
The standard deviation of the sampling distribution of a statistic. Standard error is a statistical term that measures the accuracy with which a sample represents a population. In statistics, a sample mean deviates from the actual mean of a population; this deviation is the standard error.
INVESTOPEDIA EXPLAINS 'Standard Error'
The term "standard error" is used to refer to the standard deviation of various sample statistics such as the mean or median. For example, the "standard error of the mean" refers to the standard deviation of the distribution of sample means taken from a population.
The smaller the standard error, the more representative the sample will be of the overall population. The standard error is also inversely proportional to the sample size; the larger the sample size, the smaller the standard error because the statistic will approach the actual value.

Variance
The spread between numbers in a data set, measuring Variance ... 
Mean
The simple mathematical average of a set of two or more numbers. ... 
Standard Deviation
1. A measure of the dispersion of a set of data from its mean. ... 
Sampling Error
A statistical error to which an analyst exposes a model simply ... 
Sampling
A process used in statistical analysis in which a predetermined ... 
Compound Annual Growth Rate  CAGR
The yearoveryear growth rate of an investment over a specified ...

Bonds & Fixed Income
Find The Highest Returns With The Sharpe ...

Mutual Funds & ETFs
Understanding Volatility Measurements ...

Fundamental Analysis
Monte Carlo Simulation With GBM

Mutual Funds & ETFs
Stock Market Risk: Wagging The Tails