Avatars Functions

Hi I an 100% sure what to do with the install section avatars functions?
Avatars Functions:
----------------------------------------------------------------------
User Avatars:

get_avatar(ID_OR_EMAIL,SIZE,DEFAULT)
ID_OR_EMAIL = ID or email of the user
SIZE = '16', '32', '48', '96', '128'
DEFAULT = 'mystery', 'gravatar_default', 'identicon', 'wavatar', 'monsterid'

Example:
<?php echo get_avatar(1,'32','identicon'); ?>

Blog Avatars:

get_blog_avatar(ID,SIZE,DEFAULT)
ID_OR_EMAIL = Blog ID
SIZE = '16', '32', '48', '96', '128'
DEFAULT = 'mystery', 'gravatar_default', 'identicon', 'wavatar', 'monsterid'

Example:
<?php echo get_blog_avatar(1,'32','identicon'); ?>

Please give me advice or call me stupid, its OK