Why Number values are limited in programming languages?
<pre><code>long  –9,223,372,036,854,775,808 to  9 ,223,372,036,854,775,807
int   –2,147,483,648 to 2,147,483,647
short – 32,768 to 32,767
byte  – 128 to 127
</code></pre>

<p>Why number values are limited ?. What happens If we have unique identifier for identifying a user for my web application  . Example : Facebook , Google+ . They have billions of users . What datatype are they using to store unique identifiers . If they use <code>string</code> datatypes how can they use <code>&gt;</code> and <code>&lt;</code> operators .  Is there any reason to restrict the number value?.</p>

<p>Thanks ,
Kannan</p>
