# MATLAB: Query regarding n in the equation

filter

I have implemented this equation in matlab
 In equation
h[n] = (2/L) cos ( 2 π fb n / fs ), 0≤ n < L
where L is filter length, fb center frequency of the filter (frequency to be filtered), n is number of filter points, and fs is sampling frequency on which filter is implemented.
What we mean by Filter Points (n). Can u kindly explain What is difference between L and n
And i hope that Filter length means order of Filter. Am i right??