With Google Search Ads, Google allows the advertiser to control the individual keywords you are bidding on and advertisers pay per click. With Google Local Service Ads, Google only allows certain industries to advertise. Additionally, Google only allows advertisers to bid on “job types” within their category which you then pay per lead received. For example, a real estate agent could bid on the “rentals”, and “listings”, but not individual keywords.
Moreover, Google Local Service Ads has an advantage over Google Search in that it is more simple to start, enhances your advertisement with a Google Guaranteed or Screened Badge, and you pay per lead rather than per click.