I thought I’d chime in to mention that technically, Loop type=post specifies a “post” loop-type, which happens to default to using the “post” post-type. This still totally works, but the recommended way to go about specifying a post type is with the post_type query parameter like Loop type=post post_type=post or the shorthand, Loop post_type=post. Any of these approaches achieve the same thing, but when creating post loops that refer to other custom post types, it’s better to use post_type in case you happen to have a CPT on your site that has the same name as an L&L loop type, such as a CPT named user or something like that.
Which brings us to this:
You’ll notice that in the docs, each of the query parameters mentions which type of data it accepts.
post_type - Post type(s)
Type: string, array
I’ve been meaning to rename this to make it clearer, but any time it says “array” it means this query parameter accepts an array, i.e. a comma-separated list. Same as that id parameter you’ve got. So all that to say that if you want to work with multiple post types, it’ll look a little something like this: