HI Everyone... Can someone help me, what is the essence or the use of

adOpenDynamic
adOpenForwardOnly
adOpenKeyset
adOpenStatic

adLockBatchOptimistic
adLockOptimistic
adLockPessimistic
adLockReadOnly

For Ex.
Set rs3 = New ADODB.Recordset
rs3.Open "Select * from tEmployee", cn, adOpenDynamic, adLockOptimistic

I Frequently used the adOpenDynamic, adLockOptimistic in my SQL statement, but I just want to know the Distinction, I tried to search in Google but unfortunately I didnt found an answer.....

by the way im now in my six months in using Visual basic 6.0.
Hope u can help me..
Thank you ver much

andrew_vb