Think of this like DOS.
Strings must have quotes around them if the whole string is made of up of multiple characters/words that are separated with a space.
String = "My Value"
When programming you can include quotes in two ways:
Lets be crude and use VBS to write 2 Variables inside a HTML formatted file, using: oFile.WriteLine
The title is written without quotes, and the string is written with quotes in two different ways - both are valid.
oFile.WriteLine " <html> "
oFile.WriteLine " <head> "
oFile.WriteLine " <title>" & sTitle & "</title> "
oFile.WriteLine " </head> "
oFile.WriteLine " <body lang=EN-GB link=blue vlink=blue> "
oFile.WriteLine " Method 1: " & """ & sString & """
oFile.WriteLine " Method 2: " & chr(43) & sString & chr(34)
oFile.WriteLine " </body> "
oFile.WriteLine " </html> "
I don't know exactly about PHP; but it's effectively a HTML/on-the-fly with server side ASP/VB/Javascript processing... so they should be similar.
Hope it helps.