Meaning of 'cash only'?

[Brendan Murphy]

When a property is listed as 'cash only', does that actually mean I need to have the full purchase price and closing costs in cash in the bank?  Or are there other ways to acquire this property?

Also, as a side note, I have no properties yet in my name, so home equity loans on existing properties are out of the question.

One other question related to this.  Why do sellers require cash only?  I understand that it can speed up the process, but there's one house in my market that's 'cash only' and it's been listed for almost 3 months.  So I'm not sure timeliness of the sale is their greatest concern.  My dad seems to think it's a scam, but I see far too many houses listed as 'cash only' for them all to be a scam.