I think hotmetal was inspired to write this after what I said earlier in the teen forum. To comment further on what PaladinValer said, the pentagram is the five pointed star and the pentacle being the pentagram inside a circle. The pentagram is a symbol older then the cross itself, it has been found painted on walls of babylonian ruins. The pentagram has taken different meanings over the years and has eventually been incorporated into christian symbolism, if you look hard enough for it. The pentagram to the christian represents the five wounds of Christ (two feet, two hands, and the crown). The pentagram to myself represents the four elements of the human being: body, spirit, mind, and emotions, with the top most point being the soul, the immortal embodiment of the human being. Each line of the pentagram represents that Christ died to connect each of the four elements with the fifth in Him so my soul will live on in Heaven, rather then die in Hell.
On the ankh: i've always read it to represent the cycle of birth, death, and eternal life and/or rebirth (not sure which). I do not know as much about it as the pentagram, but i'll make a statement about it in general terms later.
On the general term of the word "symbol": A symbol means something to the individual. I hate it when someone forms a set deffinition of a symbol because there will always be that ignorance to what it could mean to someone, who, instead, just believed what others said about it. Heres an example: To the christian believer, the cross could represent hope and salvation for his/her soul, but to the satanist, the cross could represent pain and suffering. Its all in how you look at it. No, i'm not saying that every symbol out there can be taken with an open mind, for there are symbols made to make a mockery of other symbols, ex: the upside cross. Those symbols are basically just a joke, a mockery. Yes, some symbols are associated with religions and such, but one could find a way to incorporate that symbol into his or her belief structure with a careful mind. Mind you that symbols alone are not deities and shouldn't be worshipped for what they personify. In the end, symbols are what you make of them.