In simple words
In Vedic astrology your life moves through nine long chapters called dashas, always in the same order. Which one you start in depends on your Moon at birth.
The Rahu dasha lasts 18 years. While you are in it, Rahu's themes colour those years. Your chart page in Vedic mode shows which dasha you are in now, with dates.
Themes
The Rahu period lasts eighteen years and brings a hunger for experience, success and the unfamiliar. It can open unusual opportunities, foreign connections and rapid change, along with restlessness and confusion at times.
What it supports
Innovation, technology, travel, unconventional paths, ambition and breaking through limits.
What it asks of you
Rahu asks you to pursue your desires with awareness. Keep your values steady while you chase the new, and check whether each goal truly serves you.