Hacking simulation game, that is as authentic as possible -- the faster you work, the easier missions get.

If you take too long in missions, you cam get traced by your targets, or turn idle servers/people hostile towards you. Absolutely upgrade your hardware if you intend to better defend yourself from such attacks. Hacking more advanced targets (e.g., a bank) is plausible with better hardware, too.
You will hack firewalls, do Denial of Service attacks, and use EMP Pulses (among other tools) to unpick your targets.

You will need to have a quick brain to beat the missions in this game....brain exercise for sure. More so than having quick fingers.
Good luck and have fun.