The Federal Open Market Committee meets eight times a year and sets a target range for the federal funds rate, such as 3.75% to 4.00%. FinVolio shows the upper bound.
Because the US dollar is the world's reserve currency, US rates set the cost of money far beyond the US.
Why it matters
Fed decisions move global bond yields, the US dollar, and therefore the Australian dollar. When US rates rise faster than Australia's, capital tends to flow to the US and the Australian dollar weakens.
See the data: Fed funds target (upper).
General information, not advice.