The term "digital option" refers to a type of financial derivative instrument that affords investors the right to either receive a predetermined payout or nothing based on the outcome of a binary event. Synonyms for digital options include binary options, all-or-nothing options, and fixed return options. Binary options refer to the two possible outcomes of the asset's price movement, either up or down, while all-or-nothing options and fixed return options describe the nature of the payout structure. These options can offer investors a unique way to gain exposure to various markets, but they can also carry high risks due to their binary nature.