Sites that generate their content dynamically often use query string parameters to tell the server what data to load.
/products.php?product=834
Search engines can identify dynamically generated content and will stop following links when there are either excessive parameters or values that look like session ids:
/products.php?product=834&view=5&channel=web&p=36346 /products.php?session=3908573476340673463
Because of this, you should to use small URLs with as few parameters as possible. If you need to track session, you should consider using cookies instead of session ids.
URL structure - google.com