All rows will be returned from your left table regardless. In the case of a left join, if the filter isn't met, all data returned from the right table will show up as null. In your case, all students will show up in your results. If the student doesn't have an instructor, i.name will be null.
Since you are only selecting a column from your left table, your join is pretty useless. I would also add i.name to your select, so you can see the results
In the case of an inner join, rows will only be returned if the join filter is met.