Before getting into stocks, ETFs and co., this distinction is worth making, it decides whether your money is gone after spending it, or keeps working for you.
Money flows out and is gone, you get consumption in return, but no asset that could be worth more later.
Money is converted into an asset that can generate income or gain in value over the long term, and which you can sell again if needed.
This distinction isn't a call to stop spending money altogether. Food, housing, a good education or even the occasional holiday are expenses that create quality of life, and that's ultimately what money is for. The point is just to be aware of which category you're choosing right now, and not to spend every leftover franc out of habit.
Every franc spent today can't also be invested. That's called opportunity cost: what could that money have achieved instead? CHF 50 per month that flows into an ETF instead of an extra subscription adds up, over 30 years, at a historical average return of 7 % per year, to an amount in the high five figures, purely through compound interest. That doesn't mean subscriptions are forbidden, it just helps you see the true cost of a habit.
Before making a bigger purchase, two questions help: does this create lasting value, or just a brief moment of pleasure? And would I spend this amount the same way if I'd had to withdraw it and pay cash first? Anyone who honestly answers both questions makes most money decisions more consciously without even trying.
Save and invest first, then spend the rest, not the other way round. Once you automatically set aside your savings on payday (see Calculators and Budget Planner), you don't need to feel guilty about the rest of the money.