How can count table column unique values in Laravel 5.6?

working with laravel 5.6 and mysql. I have following table name as projects

id  name  type  
1   tuna  bio
2   nhye  IT
3   hyuj  bio
4   tour  IT
5   ghyt  commerce

I need count type column values which are unique values. as an example in above table I need count values 3 because there are three different values like bio, IT and commerce. how can I do this?

via Chebli Mohamed