you can try it on this "help for this page" on the respective page..
U can find there...
Detail Page Link
Select this option if you want to add the link to the Custom Links section of your page layouts.
Detail Page Button
Select this option if you want to add the custom button to a record's detail page. You can only add detail page buttons to the Button Section of a page layout.
List Button
Select this option if you want to add the custom button to a list view, search result layout, or related list. You can only add list buttons to the Related List Section of a page layout or the List View and Search Result layouts.
you can try it on this "help for this page" on the respective page..
U can find there...
Detail Page Link
Select this option if you want to add the link to the Custom Links section of your page layouts.
Detail Page Button
Select this option if you want to add the custom button to a record's detail page. You can only add detail page buttons to the Button Section of a page layout.
List Button
Select this option if you want to add the custom button to a list view, search result layout, or related list. You can only add list buttons to the Related List Section of a page layout or the List View and Search Result layouts.
You can add these buttons by navigating to a particular object and there you will will find a section named Custom Buttons & Links.
I feel you can get answered to your question by using Help link shown in the top of your SFDC account.
Detail Page button's are shown on each record of the object i.e. detail page of each record.
Theyare generally used to act upon a record. But the behavior could be changed using cutom functionality.
List button's are displayed when you view a list of object records from a tab.
Here you can act upon a single or multiple records at a time.
But i will recommend you use the help link in your SFDC org for knowing the details.
Thanks ....