Yes, there is a fundamental difference between frequency and percentage, although they are often used together in data analysis.
Frequency refers to the number of times a particular value or category occurs in a data set. For example, if you have a survey with responses from 100 people, and 30 of them say they like a certain product, the frequency of people who like the product is 30.
On the other hand, percentage is a way to express the frequency in relation to the total number of observations, usually out of 100. It gives you a clearer idea of how significant that frequency is in the context of the entire data set. In our previous example, if 30 out of 100 people liked the product, the percentage would be 30%.
In summary, frequency tells you how many instances of a category exist, while percentage puts that frequency into proportion with the whole data set.