Escape Slash

The following line is using a PHP escape slash.
I am down to my last bit of money. I only have $money left.

The following line is not using a PHP escape slash.
I am down to my last bit of money. I only have $10 left.

Escape slash allows the use of characters that might otherwise confuse or disrupte the translation of a web page.
Characters such as \ and " when used in double quotation prints and echoes can cause errors, so escape slashes can help with that.