Solutions offer a way to logically group together different Synatic items such as Connections, Flows, Buffers, and Parameters.

Items in a Solution are only available to other items in the same Solution except for items in the Global Solution which are available across all solutions.
The Global Solution
The Global Solution is created by default and any items created here are available across all Solutions. The Global solutions cannot be deleted or renamed.
Creating a new Solution
You can create a new solution by selecting the green ⨁.
Adding items to a Solution
Items can be added to a solution by clicking on the green | next to the item:

Exploring a Solution
You can access an item by clicking on the expander on the left-hand side of the name to expand the children.

Importing a Solution
You can import a Solution using the import button at the top of the Solution Explorer:

You can then select the Solution file to import:

Deleting a Solution
Deleting a Solution will delete ALL related items in that Solution but not any audit or Run history.