Hybrid Attack?
whats the difference between these 2 attacks? the above is the hybrid attack and the second is the combination attack

$ ... -a 6 password.txt ?d?l?d?l

$ ... -a 1 password.txt ?d?l?d?l

both seems to work, and the result also seems to be identical.. or am i wrong
Nope, you're wrong. "-a 1 password.txt ?d?l?d?l" wouldn't do anything unless you actually had a file named "?d?l?d?l", and it would only be the same as "-a 6 password.txt ?d?l?d?l" if the file had all of the combinations of ?d?l?d?l in it.