AC DC power ports, data port connectors and dc power inputs are small internal components you would plug your dc power plug (tip part of your AC adapter cable) plug into to charge your laptop. A damaged or faulty jack can cause random issues with your laptop including randomly shutting down without any warning, flickering power lights and poor battery performance.
If for some time you’ve ever had to manipulate (wiggle) the charger cable around to get the device to receive a charge, it has become partially dislocated from the mother board or physically damaged and would need to be replaced to get the device to ever receive a proper charge.
You’ll likely need a jack replacement if the power only works when you are moving the power cord and if when plugged in the laptop looks dead (e.g. no lights, no activity etc). If you remove your battery and plug the charger into the jack and the lights stay on all the time when moving the jack around (e.g. gently move the plug from side to side, up and down) then its likely to NOT be a power jack replacement you’ll need and further investigation will be needed.
Gadget Techs can repair power ports for 95% of laptops on the market. We remove (desolder) the dc power jack and solder a brand new dc power jack to the motherboard, reassemble, test then we’re done. Average cost for these services are $100 to $125. These services generally take about an 2-3 hour to complete.