Other forms: flagships
Traditionally, the commander of a navy traveled in the flagship, which was distinguished by flying his distinctive flag. You can also call the ship in the front of a fleet the flagship.
The flagship is generally the most powerful in some way — better armed, or larger, than the ships that follow it. Ultimately, the most important thing about a flagship is that it's first. Based on this meaning, another kind of flagship is something that's the first, best, or biggest example of something — a product, store, or program, for example. Starbucks' enormous flagship coffee shop, the company's largest and fanciest shop, is in Seattle, Washington.