The word Tara means at least three things: "star", "to cross", and "the pupil of the eye".
Some of her titles include Dolma, "She who Saves"; Jnanacandra, "Moon of Wisdom"; and Tara itself can also mean "savioress".
She is the embodiment of compassion, a gift of herself to the world, a teacher, and a Buddha. As a bodhisattva she appears in female form but is not intrinsically gendered. By appearing in female form, however, she is a feminist force in a pantheon that generally held you had to be embodied as male in order to achieve enlightenment.
She holds a blue lotus flower (utpala), which strikes me as very similar in its symbolism to the Cup of Babalon. It is discussed as remaining uncontaminated in the filthiest of environments, but also as arising from that filth. It is a night-blooming flower.
Her mantra is a play on her name, using three forms of it representing three levels of enlightenment (they say "salvation", but I twitch a bit at the Christian connotations of that word - have to work on that).
The context: when I am Priestess in the Mass, different forms of the Goddess will "take me over", so to speak, sometimes depending on the day and sometimes on the congregant in front of me. I never know who's going to come out. Closing on a year ago, Green Tara, who I knew *nothing* about other than that she was Tibetan, appeared and pretty much said "you're mine now."
I took Tara as my magickal name when I was ordained, but have been reluctant to use it much because I didn't feel that I knew enough about her. I still don't know much, but I'm more comfortable with being her devotee and saying so, I think.
And, of course, the final piece of the context: note the journal's changed name, jnanacandra, the one of Tara's titles meaning Moon of Wisdom, which I like in part because of the union of the feminine Yesod with the masculine Chokmah. Not to promote myself as a font of wisdom or anything like that, but it does demonstrate some of the aspects of what I aspire to, which is the whole point of a magickal name. Plus, it's pretty ;)