Rate changes hit different parts of the economy at different speeds. Financial conditions react in minutes, housing and durable goods in a few quarters, capital spending and wages much later. The effect on inflation is the slowest of all.
Lags are why central banks talk about acting pre-emptively and why they risk overtightening: the damage from hikes already delivered is still in transit when the decision to hike again is taken. Fixed-rate mortgage markets lengthen the lag further, because households only feel the new rate when they refinance.
Example: hiking begins in month zero and peaks 500 basis points higher by month 16. Core inflation does not clearly turn until month 22, by which point the committee has stopped hiking for six months.
Related: neutral-rate, taylor-rule, target-range, recession, leading-indicator