isequal will return a single logical value, indicating whether or not the two vectors are identical.
== will give a vector with element-by-element comparison.
>> x = [1 2 3 4];
>> y = [1 2 3 5];
>> x == y
ans =
1×4 logical array
1 1 1 0
>> isequal(x,y)
ans =
logical
0
Also, isequal will work on unequal-sized vectors, and == will give an error (because the mismatch in number of elements prevents the element-by-element comparison).
