Final answer:
The buying period for television advertising that spans the TV season is called the up-front market, where advertisers can secure ad slots in advance. An affiliate is a local station broadcasting national network programs.
Step-by-step explanation:
The buying period for television advertising time that runs throughout the television season is known as the up-front market. In this market, advertisers have the opportunity to buy advertising slots before the television season begins. This enables planners and marketers to strategically allocate their budget and resources in advance, securing premium time slots and potentially getting better rates than later in the season.
A local station that broadcasts national network programming is referred to as an affiliate. These affiliates often purchase advertising slots through the up-front market as well, as part of their strategy to align with the national network's programming and target audience.