Keep in mind, distributions should be distinguished from allocations of income to partners, which can result in a taxable event notwithstanding a distribution.
When a distribution is made, the partner’s adjusted basis in the partnership is decreased by the amount of money or property distributed. The partner would only recognize gain or loss on the distribution when the amount exceeds the adjusted basis of the partner’s interest.
The distinction between the two is whether the person remains a partner in the partnership after the distribution.
A liquidating distribution occurs when either the partnership itself liquidates and distributes all of its property to the partners, or when the partnership remains ongoing and one of its partners redeems all their interest.
Distributions made to partners may or may not be in proportion to their interest in the partnership.