What is the song "ANNIE LAURIE" About?

PLZ HELP ME! IM SINGLE STRAIT AND 13 ;)
IMMA GIRL TOO LOL

the song is written in old english but it sounds like an old love song. here is why:

"Maxwellton braes are bonnie,

Where early fa's the dew,

And 'twas there that Annie Laurie

Gave me her promise true.

Gave me her promise true,

Which ne'er forgot will be,

And for bonnie Annie Laurie,

I lay me doon and dee."

this verse talks about a relationship.

"Her brow is like the snowdrift,

Her throat is like a swan,

Her face it is the fairest

That e'er the sun shone on.

That e'er the sun shone on,

And dark blue is her ee,

And for bonnie Annie Laurie

I lay me doon and dee."

the second verse is basically compliments to someone.

And "And she's a' the world to me" In new english is "and she's the world to me."

But please do not come after me for a relationship because I am already engaged to my fiance and i would never leave her side.