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 Saturn dasha lasts 19 years. While you are in it, Saturn's themes colour those years. Your chart page in Vedic mode shows which dasha you are in now, with dates.
Themes
A Saturn period runs for nineteen years and favours structure over speed. Life tends to ask for patience, responsibility and steady effort. Results come, but usually later than you hoped and more solidly than you expected. Many people find this is when they finally build the habits, skills and commitments that carry the rest of their life.
What it supports
Long projects, discipline, careful planning, service to others, and anything that rewards showing up again and again. Quiet, unglamorous work done well is noticed in this period. Saturn also has a nurturing side: it protects what you have by asking you to tend it.
What it asks of you
Saturn asks you to accept limits without becoming them. When progress feels slow, shorten the horizon: one honest step a day. Watch for heaviness of mood and meet it with routine, rest and people you trust. The aim is not to endure the period but to grow sturdier through it.