Often you need to perform intermediate steps in a calculation but have no need to see the results. By suppressing the output you save memory to store the notebook and may even save formatting time. You will also be able to see the important parts of the notebook more easily.
You can suppress output in the Wolfram Language by placing a semicolon (;) at the end of the line:
For example, consider:
Suppress the output:
This creates a small table of values and exports it to a text file. There is no point in seeing the numbers, so the result is suppressed:
You can also use ; to condense multiple lines into a single line. The output here is 2 since only the output of the last statement, b=2, is displayed: