Gamma, beta and alpha radiation are all alike because:

they all have the same mass

they all have the same charge

they all can be emitted from the nucleus of an atom

they all have the same energy

Alpha, beta and gamma radiation are all types of radiation that can be emitted from the nucleus of an atom. Apart from this they are different. Alpha radiation consists of a helium nucleus, beta radiation consists of an electron (or positron) and gamma radiation consists of very high energy electromagnetic radiation.