Active Tab Block
Set the current tab that you're in as an active tab. Active tab in this context is a tab where the block in the web interaction category or a block that is required a tab like a take screenshot block will execute.
For example, when you want to take a screenshot or execute a javascript code on a website that you're in, you can use the active tab first before connecting others block like the take a screenshot or javascript code block.
Because this block uses the tab you're in as an active tab, you need to execute the workflow from the Automa popup or use the keyboard shortcut trigger.