One. It is performing Tawaf of the Ka'bah. The condition of Umrah is entering into Ihram. However, some have said that the pillars of Umrah are three, namely:
(1) Entering into Ihram.
(2) Performing Tawaf.
(3) Performing Sa'i.
It should be noted that these pillars are also the obligatory acts of Umrah.