@Muhammad Tanveer: if you take 123456 (without commas, semicolons or spaces), it is one (huge) number.
You can create a vector both by enclosing the elements in square brackets like v=[1 2 3 4 5] or using commas, like v=[1,2,3,4,5]. They mean the very same: a vector (matrix) of 1 row and 5 columns. It is up to you.
If you used a semicolon (;), then v=[1;2;3;4;5] means something else: a vector of 5 rows and one single column.