14/26 as a percentage is 53.85%. This rounded value gives a quick sense of how large the fraction is compared to a whole.
The fraction 14/26 can be simplified to 7/13, but whether you keep it as 14/26 or 7/13, the percentage stays the same. Knowing the percentage helps you compare this number to other values that are already expressed in percent form.
In everyday situations, you might see this percentage when looking at test scores, discounts, or data sets. Seeing 53.85% tells you that a little more than half of the total is represented.