What is the difference between using conv function and manual coding method using MATLAB?

Here I Have mentioned two different options and the option 01 has used conv function and the option 02 has used manual coding method to find discrete Convolution.

Option 1

clc
clear all 
close all 
n = 1: 1: 1000; 
N = randn (1,1000); 
s = 10*cos(0.05*n);
figure (1) 
plot (s,'r') 
x = s + N;
figure (2) 
plot (x,'g') 
h = 0.1*ones(1,10);
y1=conv (x,h);
figure (3)
plot (y1)
 
figure (4) 
plot (s,'r')
hold on 
plot (x,'g')
hold on
plot (y1)

Option 2

m = length (x);
n = length (h); 
 
X = [x,zeros(1,n)];
H = [h,zeros(1,m)];
 
for i = 1: n+m-1 
    
    Y(i) = 0; 
    for j = 1: m
        if (i - j+1 > 0)
            
            Y(i) = Y(i)+X(j)*H(i-j+1);
        else 
        end 
    end 
end 
 
 
figure (5) 
plot (Y); 
hold on

Answer 1

[Bruno Luong]

Your twin brother/sister/class mate is faster, he/she asked the same question earlier.

Don't copy the same answer, your teacher might notice it.