The "greater than" symbol (>) is used to express a larger value.  For example, 
if (x > 10) means "if X is more than 10."  Also called a "right arrow," it is also used to transfer the output of a process.  For example, in DOS and Windows, the expression 
dir *.* > names places the results of the directory listing into a file called NAMES. 
In programming, double "greater than" characters (>>) are sometimes used as a right shift symbol, which shifts bits to the right by four bits.
The "greater than" is also used to close HTML and XML tags, while the "less than" (<) symbol is used to begin them, as in the following examples:
  <HTML>   </HTML>
  <HEAD>   </HEAD>
  <TR>     </TR>
  <TD>     </TD>
  <B>      </B>