Difference between distinct count() and count(distinct) in Sql Server

1) when u write this way..

select   count(distinct ACODE) from dbo.Table_1

then it counts for different values like my table(dbo.table_1) having ACODE column which has certain values

ACODE
2010
2010
2009
2011
2011
2009
2010
2011

now if i execute first query will get ans = 3, bcoz it counts only distinct values.

2)now,

select  distinct count(ACODE) from dbo.Table_1

if u execute this then u will get answer = 8

bcoz, it has 3 times -2010, 3 times - 2011 , and 2 times - 2009

this count for all the records and give output, and does not give count for distinct value.

3)if u want to analyse it more deeply then try it by exicuting this query..

select   distinct count(ACODE),ACODE from dbo.Table_1 group by ACODE

hope this help..