The Senate "cools" legislation from the house like a saucer cools coffee. The Senate approves all presidential appointments and ratifies treaties while the house initiates revenue bills.
The Senate has vital powers as stipulated in the constitution under the " advice and consent" provisions, Article II, section 2, to; ratify treaties which require a two-thirds majority of the senators present and a simple majority to approve important public appointments i.e., ambassador and cabinet members.