hard start

[accent]

If I don't run the car for a few days, I have to use another car plus a jumper starter to jump start it. What is wrong with it?

[3X00-Modified]

bad battery... or you have something drawing current on it when it sitting...

[Money pit Beretta]

In the old days a sticking starter solenoid would drain the battery.

[accent]

bad battery... or you have something drawing current on it when it sitting...

Yes the battery in the car is dead but the thing is i have to use another car plus a jump starter to jump start the car. Something wrong with the engine or starter?

[Money pit Beretta]

The engine is fine. You also know that the starter is working, but may be drawing too many amps.

[accent]

The engine is fine. You also know that the starter is working, but may be drawing too many amps.

Does it mean many cables in the car need to be replaced?

[Asylum]

With a good battery a car should be able to sit for a month or more and still start without an issue.
My Quad sits for 3 or 4 months at a time and has always started right up. Get some competent garage to do a Load Test on the battery.

[Koots]

A weak battery will definitely do what you're saying, especially when being boosted by another vehicle.

[3X00-Modified]

bad battery... or you have something drawing current on it when it sitting...

Yes the battery in the car is dead but the thing is i have to use another car plus a jump starter to jump start the car. Something wrong with the engine or starter?

Bad battery means it dies over two days... Something wrong with it it's not holding a charge.. replace it.

[Rettax3]

It is possible you have something draining the battery dead over a few days, but like everyone else is saying, probably the battery itself is bad. Have it tested, replace if bad
If that doesn't fix it then get a multi-meter with a decent amp check capability -Harbor Freight Tools sells cheapies for under ten bucks that will handle ten amps, that will work for you. Connect the probes of the meter between the battery's negative cable and the battery negative terminal itself, and read the current draw on the meter. You should only have a fraction of an amp with the ignition off, doors closed, etc. If you see anything higher than .4 or .5 amp, you have something killing the battery, and even a new one won't survive for long. If your car has an aftermarket stereo, alarm system, amps, anything like that, that would be the place to start checking. You can pull the fuses one at a time while watching the meter to help track-down what circuit is drawing current, but since the door has to be open to access the fuse-block, you will get an amperage reading on that circuit.
A bad starter can prevent a battery from being able to crank the engine, and give all the indications of a weak battery, but it shouldn't matter in that case if the car was sitting for five minutes or five days, so that doesn't fit with your description of the problem.