Definitions as per the American Marketing Association:
Continuous Media Pattern:A timing pattern used in a media plan whereby the advertising messages are scheduled continuously throughout the time period covered by the media plan.
Flighting:An advertising continuity or timing pattern in which advertising messages are scheduled to run during intervals of time that are separated by periods in which no advertising messages appear for the advertised item. Any period of time during which the messages are appearing is called a flight.
Pulsing:An advertising timing or continuity pattern in which there is noted variation of media spending in the media schedule. There is some spending during all periods of the schedule, but there are periods in which the spending is notably heavier than others. This approach stands in contrast to a continuous media pattern in which equal amounts of spending are allocated to all time periods of the schedule.