You can quickly spin up additional nodes to your network as it grows and designate the new node as either a watcher or a validator. The mechanics of this are simple:
From the dashboard of an existing network, click on <Add node>
There is a quick add: which lets you spin up a node automatically configured based on the main network, or a custom settings node where you can set up different cloud servers and locations.
You can choose whether the new node is a validator or a watcher node.
What's a Validator or a Watcher?
Watcher nodes monitor the network, submit transactions, and store the current version of the ledger
They do not participate in consensus.
If a node is set up to participate in consensus, it is called a validator.
Validators serve a purpose somewhat similar to miners - they agree on sets of transactions every several seconds via consensus and update the global ledger.
The more validator nodes in the network, the better.