All are redeemable points; you can spend them on stays or whatever.

The sole purpose Base Points serve is to render status (note that the period now seems to be any 12 month period, given the new rotary system even HH seems not to be very clear on):

To Qualify for DIAMOND VIP: As of Jan 1, 2003, you'll need 28 qualifying stays or 60 qualifying nights or to earn 100,000 base points in a calendar year at HHonors hotels.

To Qualify for GOLD VIP: As of Jan 1, 2003, you'll need 16 qualifying stays or 36 qualifying nights or earn 60,000 base points per calendar year at HHonors hotels.

To Qualify for SILVER VIP: As of Jan 1, 2003, you'll need 4 qualifying stays or 10 qualifying nights in a calendar year at HHonors hotels.

To Qualify for BLUE VIP (no VIP, really...): As of Jan 1, 2003, Blue is entry level and requires no minimum qualifying stays, nights or earned base points per calendar year at HHonors hotels.