The Post ID Component is for controlling content visibility based on a post’s ID.
Here you select whether the current post’s ID should be equal to or not equal to the selected post IDs.
B) User ID
Here you enter the post ID.
What are Post IDs?
WordPress assigns each page and post of your website a unique post ID. If you’re unsure how to find the ID of a page or post, please see these instructions from Elegant Themes.