Chronologically, analog hearing aids were here before the digital hearing aids. The digital hearing aids evolved with technology in the last decades. Today Digital hearing aids are more common.
Analog and digital hearing aid both amplify the sounds and voices so you can hear it. The concept is the same, so the basic components are same. A microphone to absorb the sounds from the surrounding and transforms it to electric signal. Amplifier that amplifies and manipulates the electric signal Speaker to transforms the electric signal back to acoustics and to send it to the ear.
The main difference between analog and digital hearing aids is the way it handles the electric signal. On analog hearing aids, the electric signal from the microphone is amplified “as is” and it is then transformed back to acoustics using the speaker. On a digital hearing aid, the electric signal from the microphone is transformed into a digital binary code.
Once the signal is “digitized”, the advance chip inside hearing aid can manage the signal.. It can perform millions of manipulations in fraction of a second.Afterwards, the signal is transformed back to a regular electric signal and then the speaker changes it back to acoustic sounds.
Even if you got the most sophisticated hearing aid, it has to be handled by a skillful hearing aids specialist.(Audiologist)