
width 100 means the size of the particular td or table is 100 pixels.
width 100 means the size of the particular td or table is eqaul to the length of the td or table which is have this td or table.
Both of declarations are eqaul in firefox. It consider both of them have a size of 100 pixels.

i agree with the previous ans

no diffrence

Copy this code and make it html page
(see the difference between width ”100” and width ”100 ”)
<html>
<head>
<title>Untitled Document</title>
</head>
<body>
<table width "100 " border "2" cellspacing "0" cellpadding "0">
<tr>
<td>width "100 "</td>
</tr>
</table>
<br />
<table width "100" border "2" cellspacing "0" cellpadding "0">
<tr>
<td>width "100"</td>
</tr>
</table>
</body>
</html>

There is lot of difference between width 100 and width 100 . Suppose we have create a table.if width 100 will be 100 than it would be fixed width.In other hand 100 means table will display in its full view and it could be change according the resolution.

Width:
100 Table/ID width
100PxWidth:
100 Table/ID width Whole Page even
1024 or
1440 Px Resolution or more..

width 100 is fixed width.
Suppose we have created a table with the width of 100. It will show in browser with fixed width of 100 in any resolution. But in 100 width your table will strech according to the resolution of your monitor.