How does the structure of a cell enable it to carry out a particular function?

If anyone could possibly help me with this it would be much appreciated.

How does the structure of a :
1] nerve cell,
2] palisade cell,
3] xylem
4] and ciliated cell
enable it to carry out a particular function?

Please help, am in desperate need of knowledge.

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).