The main merge board is where you will spend much of your time in Travel Town. This is where you'll find the producers and items you have earned, the orders you have to fulfill, and the item inventory. By fulfilling orders you will earn items and Coins that can then be used to purchase new buildings  and upgrade your town.

Items can be created by tapping on a Producer. Each tap on a producer costs one energy ⚡ and it is important to note that some producers require multiple taps in order to create an item. Producers can be earned by merging certain items to completion or by purchasing and upgrading buildings in your town. 

Merging items will combine them into a new item in the same series. When an item is discovered for the first time it will be added to your collections and include a gift of one diamond. Check out the article about Collections to learn more.