Google Ads is a real-time auction system. Every time someone searches a term, Google auctions the space at the top of the results and picks who to show based on how much you're willing to pay and how relevant your ad is. You pay only when someone clicks, not for the impression.
The difference from social is intent. On Meta you intercept people scrolling the feed who aren't searching for you: you create the demand. On Google you intercept people already searching for a solution, right now. It's warmer traffic, so usually more expensive per click but closer to the purchase.
What it costs depends on three things: how competitive the term is, how relevant your ad is, and how well your page converts. Cost per click in Italian professional niches ranges from a few cents to several euros. But the number that matters isn't cost per click: it's cost per booked call. A €2 click that converts beats a €0.20 click that never does.
The most common mistake is sending ads to the home page. Someone searching 'lawyer for tax notices' who lands on a generic firm's home page doesn't find the answer and leaves. You need a landing dedicated to that search, with that problem at the top. It's the same principle by which, on Meta, for RicorsoCartelle.it we kept cost per click at €0.05 with a 4.91% CTR: ad and page talking about the same thing.
Google Ads is worth it when there's existing demand to intercept: a service people search by name, 'consultation', 'quote', 'how to challenge'. If your service is new or people don't know they need it, demand has to be created first, and social does that better. Often the right answer is using them together, not choosing.
Measurement is the part almost everyone skips. Without tracked conversions, a phone call, a form, a booking, Google optimizes for clicks, not clients. The first job on any account isn't writing ads: it's wiring conversion events, so the algorithm learns to bring the right people.
If you don't know whether your bottleneck is traffic or what happens after the click, the free 2-minute audit on this site analyzes the 4 layers of your engine and tells you where to start.