Panchanga or Panchang is Hindu Almanac. The literal translation of Panchanga is "Five Limbs". The five energies it represents are considered for selecting an appropriate and auspicious time for ceremonies or certain actions. Panchanga is consulted in matters of timing, i.e. calculating muhurta concerning marriage, education, travel and agriculture to name a few. It is very interesting to note the importance given to Sun and Moon in ascertaining a good time. While fixing a muhurta, we cannot possibly choose a time that is perfect in all respects, we therefore should try to choose a time that would do more good than bad.
The five limbs and a brief description is as follows:
Tithi (along with Paksha): A tithi means a lunar day. A lunar day is about 0.95 of a normal day. When the Moon moves towards the Sun, it is called Krishna Paksha, otherwise its Shukla Paksha. When the Sun and Moon are closer to each other, it is Amavasya and when they are 180 degrees apart, it becomes Poornima.
Vaar (Day of the weeks): The days of the week along with the ruler planet in the brackets are - Sunday (Sun), Monday (Moon), Tuesday (Mars), Wednesday (Mercury), Thursday (Jupiter), Friday (Venus) and Saturday (Saturn).
Nakshatra (Constellation): Apart from the 12 signs, there are 27 constellations that are like "mansions" or "houses". The planets visit these houses while on their journeys through the skies. Nakshatra is a generic term and all planets are in one Nakshatra or the other at any given time. However, when someone says Janma Nakshatra or daily Nakshatra, he/she specifically means Moon Nakshatra.
Yoga: Yoga means combination. In this context of Panchanga, it means it means a particular combination of Moon and Sun. This combination is said to affect a person's health.
Karana: Karana means half a lunar day. There are 11 Karanas.