This is a natural follow-up from the other post Find an inbox layout of your choice. With the different layouts, you get a chance to determine a format that best helps you use Gmail to suit your workflow. However, there is always the matter of fine-tuning things; such as organizing the emails under labels in Gmail and bundles in Inbox that can add an extra wing of efficiency.
When Gmail was launched in 2004, one of their pioneering features were labels. We had previously seen folders - across both email clients and erstwhile web email services - which were like vaults where you can move your messages to; but what Gmail brought with labels were revolutionary, as the labels were like post-its - you can attach several of them to a single message and that message can be viewed under all the labels it has been labeled with. So, in cases where a message may fall under multiple labels, there was no further need to copy that message to be placed inside multiple folder but the simple task of assigning the necessary labels to that message and be done with.
Filters helps automate the process of applying specific labels (among many other things) to a matching message based on the specified criteria. It can also help apply the mandated label to matching previous conversations, thereby ensuring consistency towards organizing your Inbox.
Inbox by Gmail can also organize your emails with labels you create, or existing labels, like "Social" and "Finance." Inbox can sort your labels into bundles or list them in the Menu. Bundles helps group similar emails together so you can better manage them.