In SQL, the main difference between the GROUP BY() and ORDER BY() functions is that ORDER BY() sorts returned values by column name, in ascending or descending order, while GROUP BY() sorts the result sets of aggregate functions like sum, count, minimum, or maximum.
Imagine a table of cats with a name, age, and color column. You would write a query to order the list by name alphabetically like this:
"SELECT * FROM cats ORDER BY name ASC"
While you would return the number of cats older than 5 years old in ascending order by name like this:
"SELECT name, COUNT(age) FROM cats WHERE age >= '5' GROUP BY name ASC"
Combined, ORDER BY() and COUNT BY() can perform more complex queries, such as when you want to select the most common color and return with the count:
"SELECT color, COUNT(color) FROM cats GROUP BY color ORDER BY COUNT(color) DESC LIMIT 1"