What's the difference between i.e. and e.g.?
mid-14c., "a beholding, looking at," also "keeping in mind," from Old French consideracion (12c., Modern French considération), from Latin considerationem (nominative consideratio) "consideration, contemplation, reflection," noun of action from past participle stem of considerare (see consider). Meaning "a taking into account" is from mid-15c.; that of "something given in payment" is from c.1600.
in contract law, an inducement given to enter into a contract that is sufficient to render the promise enforceable in the courts. The technical requirement is either a detriment incurred by the person making the promise or a benefit received by the other person. Thus, the person seeking to enforce the promise must have paid, or bound himself to pay, money, parted with goods, spent time in labour, or foregone some profit or legal right. In a contract for the sale of goods, the money paid is the consideration for the vendor, and the property sold is the consideration for the purchaser.