Benefic and malefic planets
Benefics (shubha grahas) are planets of a gentle, supportive nature; malefics (papa grahas) are harsher and more testing. Jupiter and Venus are the chief natural benefics; Saturn, Mars, Rahu, Ketu and, mildly, the Sun are malefics.
Also known as: shubh graha, papa graha, krura graha, natural benefic, natural malefic, benefic planets
Jupiter and Venus are always natural benefics. The Moon is a benefic when waxing and bright, and Mercury is one unless it is joined by malefics. The Sun is a mild malefic; Mars and Saturn are stronger ones, and Rahu and Ketu are counted as malefics too.
“Malefic” does not mean evil. Saturn brings discipline, endurance and maturity; Mars brings courage and drive. Malefics often do well in the 3rd, 6th, 10th and 11th houses, the upachayas, where struggle turns into growth, while benefics usually help most in the kendras and trikonas.
This natural classification is only the first layer. Each planet also becomes a functional benefic or malefic for your particular ascendant, depending on the houses it rules, and in practice that often matters more.