Can I play the same minecraft on more than one computer?

I have minecraft on xbox but I wanted more to I'm thinking of getting it on PC. BUT the computer I share with my sisters only works if i have a charger connected to it. So I might get a new one who knows, but if i do, could I play the same world or same minecraft as this computer? Also who knows how to fix that computer problem so I don't have to connect the charger for it it to work?! So 2 questions in one. Thanks. And also do I need Wi-Fi to play minecraft solo? Obviously I do for servers And multiplayer so yeah.

Don't know

You can login to the same account on separate computers at the same time, and play online servers and multiplayer at the same time too. BUT, you can't go on the same servers with both logged in computers. For Example. If Person A went onto one server, then Person B can't access that server until Person A Leaves it, if Person B tries to access that server, Person A will be kicked from that server and you will replace them.

You can't play the same games on LAN multiplayer (I don't think anyway) as it will confuse your internet router.

Playing minecraft does not require an internet connection if you are playing solo, however, you will need an internet connection to login, sorry. (Unless your computer has already remembered. If not, download a cracked minecraft.)

ALSO, if you install minecraft on a separate pc and you want YOUR saves, you will have to either make them again or copy them from this source on your old computer to your new computer through USB stick, E-Mail, Camelback I don't really care. (Hold the Win Key+R, or type or find RUN in your start menu, then navigate to the following path: C:\Users\User\AppData\Roaming\.minecraft… (Tip, just copy and paste it into your start menu.)

The charger problem sounds like your battery connection is faulty, or the battery no longer charges. If you look on the back, side or top of the laptop battery, you should see some contact plates, these may be obstructed or dirty, check the line up in the battery compartment of the PC too. If not, try purchasing a new battery before gung ho-ing it and purchasing a new PC. Just search your laptop model's battery on eBay or visit your local PC shop, they should have one, depending on the PC brand anyway.

If you have anymore questions, please do not hesitate to ask through comments!

Hope I helped
Aaron