[NOP 4.1] commonsettings.staticfilescachecontrol - what is it?

Hi SEO guys tell me, i should set for the static files (like pictures) a longer cache time. I check in admin > all settings and found commonsettings.staticfilescachecontrol can i read somewhere what files it's means?

I have there default value: public,max-age=604800  it's minutes? hours? days?

Can someone tell me is it good idea to increase it? what impact for my store make this change? is any risk?

Is it possible to change cache time for pictures?

Thx!

It's in seconds. Please feel free to increase if required (e.g. for 1 year = 31536000)

Hi! thx Andrei!

Is this include pictures? or maybe i can found somewhere list of "static files"?

If it not include pictures is other place when i can change it?

Right. This setting affects pictures as well