Chandra (Moon) mahadasha for Karka (Cancer) Moon sign

In the Vimshottari system a life moves through nine long periods, each ruled by one planet. The planet that rules the period sets the tone of those years: the areas of life that come forward, and the kind of effort that pays.

The Moon mahadasha lasts 10 years in full. Most people meet it partway through, so the part they live through can be shorter.

The Moon stands for the mind, feelings, the mother and home. Its period tends to make family, comfort and moods more central, and brings more contact with people and the public.

Counted from Cancer as the first house, Moon rules Cancer, your 1st house. During its period the matters of that house come forward:

The 1st house is you yourself: your direction, confidence and the way you meet the world. Its lord's period tends to put you at the centre of your own story and to favour fresh starts you choose for yourself.

Moon is itself the lord of Cancer. Its period tends to feel close to your own nature, and what it brings is usually easier to own and make use of.

Which mahadasha you are in, and when it began, depends on the Moon's nakshatra at the moment you were born, so it is personal to you. Even within the Moon mahadasha, where the planet sits in your own chart and the sub-periods inside it shape the years more than your Moon sign alone.