Task statuses and states sound similar, but they're very different concepts in Jetpack Workflow.
Status
Task statuses will refer to whether a task is not started, in progress or complete. You'll see this status next to a task when you're in a project or on the My Work or Team Work pages as shown in the screenshots below.
State
Task states are going to be referring to a task being up next or blocked. These states can help you determine where your time is best being spent or when someone might be stuck.
"Next" just means the task is up next in the project's task order. This state is automatically applied to the next task after the one before it is marked as completed.
"Blocked" indicates the task has the blocked flag enabled. This means there is something standing in the way of this task being completed like missing information or outstanding questions. Common examples of when firms apply the blocked state is when something might be outside of their control, such as waiting on client documents, third party delays, their client is out of office, and so forth.
It is strongly recommended that team members leave notes in the task comment section detailing why the task might be held up for transparency.
"Overdue" means that this task has not been completed by the due date. When a task becomes overdue, it's due date color will automatically change to red as seen in the image below where all tasks are overdue.
Keep in mind, tasks can technically have multiple states but will only ever be listed as one status. (ex: a task can be both blocked and next but it's status can only be either not started, in progress or completed).