There are a few Symbols used in Jewish prayer. These include such things as:
Tefillin
Also called Phylacteries is a set of small black boxes containing parchment from the Torah. They are worn by observant Jews during morning prayer. One is strapped to the hand and arm, and the other in worn on the head. Wearing the Tefillin is meant to remind Jews or the worshipper of God, and their physical and intellectual commitment to God and the covenant.
Menorah
The Menorah is the seven branched candle or candelabrum. It is one of the most commonly known Jewish symbols, and in a synagogue is used lit in the evenings and cleaned in the morning (with fresh wicks and olive oil). It is lit as a reminder to follow God and his commandments.
Yarmulke
Also the kippah is a piece of Jewish dress, worn on ones head during prayer. It is common among men, but is not mandatory. It is a reminder to follow God and that God is always above them.
