A graha is not read in isolation but through the several tables that make up a Panchanga and a chart. It rules Thursday in the seven-day week, which in the Indian tradition as in the European one is named for the seven visible grahas in the order of the planetary hours. It holds 16 years of the Vimshottari dasha cycle, and it is lord of three of the twenty-seven nakshatras, Punarvasu, Vishakha and Purva Bhadrapada, spaced nine apart so that the nine grahas cover the twenty-seven exactly three times over.
The Vimshottari dasha system divides a notional lifetime of 120 years among the nine grahas in a fixed order, Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn and Mercury, with fixed lengths that sum to exactly 120. Which period a person begins life in is determined by the nakshatra the Moon occupied at birth, and how far through that period, by how far through the nakshatra the Moon had travelled.
In the scheme of dignities it is exalted in Cancer and in its fall in Capricorn, and dignity is what the classical rules for strength are built on, since a graha in its own sign or its exaltation is read as able to act and one in its fall as constrained.
Jupiter is the great benefic of the system and moves through roughly one sign a year, so its transit is the one most often used to characterise a year in popular practice. Its dasha of sixteen years is among the longest, which means that whether it falls within a given life, and at what age, is one of the more consequential facts a chart yields under this method.