the options you have depend, of course, on your hearing aid.
Hearing as “natural” as possible, just nal-nl2 fitting with pinna-simulation as directionality, no noise-reduction of any kind.
Same as 1, but auto-switch to “speech in noise” and a little noise-reduction. This I use when I have problems with speech in noise and / or when I find some static noise annoying (esp. when cooking). I could use this as program 1, obviously, but I don´t like it when the sound changes.
Live Music: Less amplification, less compression. This is for playing piano, singing, live-music and sometimes tv, when it get´s a little louder
Slot 4 is for experimenting, at the moment it´s tv/music.
Maybe more useful for you is the following information. You can change the following aspects in different programs:
a) Features, depending on your aid there are different ways of digital signal processing. Those are noise-reduction, impulse-reduction (for clattering plates, for instance) and advanced features such as reverb-reduction. Please test carefully which features really help you, because all features also distort the sound and may even decrease your speech undestanding.
b) Directionality: The way your aids focus to a certain direction. For instance, if you are talking to someone in front of you in a noisy place, you will want the aid to focus to the front. If you are driving a car (you are the driver) this won´t work, of course, because the talker will sit on side of you. There are lots of directionality options. Some aids offer automatic adjustment, too, and some can be controlled in some way (change the focus of your aid with your smartphone, for instance). It depends on yourself how much focus you need, because your brain can also focus on a certain speaker. But in general, this is more difficult for people with hearing aids, and the directionality is the best and most effective way to improve your signal-to-noise-ratio for speech in noise (esp. for speech in speech-noise).
c) Amplification / compression. You can set the amplification for different input levels and different frequencies. This results in certain compression ratios. Usually, it´s easier to understand speech when the speech-area is not compressed too much. That is why you need different compression settings for soft speech and for speech in noise. Soft speech is in, say, 40 dB to 50 dB, so that area should not be compressed too much. Loud speech (in noise) is in 70 dB to 80 dB, so that area should not bee compressed too much. You can´t have both at once, so you either need different programs or an automatic detection.
The combination of a, b and c gives you endless possibilities, and it´s obvious that you cannot try all of them. Also, having a hundred programs won´t help you. You could take notes in which situations you hear well and in which not, and then either add programs or change the settings of your automatic detection of some kind.