Field boundaries shown to facilitate understanding

[anhnha]

Field boundaries shown to facilitate understanding.

Is this a sentence?
What is the difference between #1 and #2?
1. Field boundaries shown to facilitate understanding.
2. Field boundaries are shown to facilitate understanding.
Thank you.

[bhaisahab]

Field boundaries shown to facilitate understanding.

Is this a sentence?
What is the difference between #1 and #2?
1. Field boundaries shown to facilitate understanding.
2. Field boundaries are shown to facilitate understanding.
Thank you.

Without more context both are unclear as to meaning.

[anhnha]

Here is context. It is in my slide.

[Rover_KE]

1. Field boundaries shown to facilitate understanding. It is not a sentence as it has no main verb. As a caption to the chart it's perfectly understandable (or will be to those who understand the chart).

2. Field boundaries are shown to facilitate understanding. This is a sentence: 'are' makes it so.

Rover

[5jj]

Originally Posted by anhnha
1. Field boundaries shown to facilitate understanding. It is not a sentence as it has no main verb. As a caption to the chart it's perfectly understandable (or will be to those who understand the chart).

2. Field boundaries are shown to facilitate understanding. This is a sentence: 'are' makes it so.

Thanks, Rover. (OK, OK, I know we are supposed just to 'like' posts that have done their job, but I, a native speaker, had no idea how to respond to the OP). I am posting this 'thanks' to assure learners that they need not despair if they had no idea what the OP was about.

[SoothingDave]

To me, the "are" was understood in the first sentence.

[Vaedoris]

Is "sentence" 1 a noun phrase?

[anhnha]

Thank you very much. It is really what I want to know.

I think that "Field boundaries shown to facilitate understanding" can be a subject in a sentence and we can make a sentence like this:
Field boundaries shown to facilitate understanding are in blue.
And there is a point that is not clear to me, can you explain about it?
When we write "Field boundaries shown to facilitate understanding" as a caption to a chart or something else, we cannot put a period at the end of the phrase like this:
Field boundaries shown to facilitate understanding.
It is only what I think, is it right?