There were 13 collection boxes in the Bais Hamikdash. On each was written one of the following; new shikalim, old shikalim, kinim, birds for an olah, wood, levonah [frankincense], gold for the utensils, and 6 said nidavas for donations.

The new shikalim box was for the new shikalim for this year.

The old shikalim box was for the shikalim for last year.

The Kinim box was for torim birds.

The Birds for an olah box was for the yonah birds.

R’ Yehudah says these last 2 were for olos. The chachamim say the kinim box was for birds for both olos and chatas and the Birds for olah box was only for olos.

Shikalim 6:6

If someone says, ‘I want to give wood’, he should give blocks for the mizbaiach. If he wants to give Frankincense, he should give a kometz [a fistful]. If he wants to give gold he should give no less than a dinar.

The 6 collection boxes were used to collect monies for olos. The olas are burned on the mizbaiach and the skin goes to the cohanim.