When Roger Ailes ran FoxNews, they would have a staff meeting every morning where they would discuss which Republican talking points they would be pushing that day. Ailes was connected with the upper echelon of the Republican Party, so he would consult with the party before each meeting. The management and on-air talent at Fox would agree on certain points or phrases that would be repeated verbatim on each of the network's shows, so that viewers would get a consistent and steady stream of that day's messages. If the overnight ratings went up, then the previous day's phrases would be re-inserted into the next day's shows. If the ratings stagnated, then they'd come up with a new set of talking points to try out on the loyal viewers.
The current process is similar, although nowadays Fox will get many of their talking points directly from President Trump himself. So, if Trump makes a claim on Twitter or during one of his helicopter gaggles, Fox will immediately incorporate that claim into every show on the network -- repeating Trump's exact phrasing. This is partly to show a unified message to the viewers, but also partly to capture the attention span of Trump himself (if he sees his own words being used on Fox, he's more likely to praise the network).