Buddhism is a philosophy and a way of life, where mindfulness and acceptance of the life the way it is (as a suffering and impermanence) play key roles.
Gassho means to put the hands together. Signifies the oneness of a Buddha (practitioner or master of Buddhism, or simply the person who puts her or his hands together) and all beings, and also expresses reverence and gratitude.
The example picture from:
Laurieledingham.co.uk