This is probably the most important article you should read and understand
What is a connection?
A connection transfers data from sheets between spreadsheets.
A connection requires updates to run.
What is an update?
If you only use one source (includes append), it requires one update each time you are running it
A consolidate (multiple sources) requires X depending on the number of sheets you are merging.
A connection takes data form the source and transfers it to the destination. In the destination it creates a new sheet to hold the data. The name of the connection always equals the sheet name.