When you expose film to light at proper exposure levels to eventually get a photo it does not create a visible change to the film. The chemical reaction of the film's emulsion to light is not a visible one unless one grossly overexposes the film in which case it will go from being semi-transparent to being solidly opaque. A properly exposed undeveloped negative is what we call a latent image at that point. We must then use developing chemicals to cause additional chemical reactions that can make visible the chemical differences between areas that received more or less light during the exposure of the film.

At this point the negative (or positive in the case of some types of film) can be used to create a print or can be scanned to a digital file. Most commercial mini-labs, such as those located in places such as CVS or Walgreen's, that include scanning services as part of the developing package will run the entire film strip through an automatic scanner before cutting the long strip of negatives into several shorter strips and placing them in protective sleeves. They do it this way because it is less labor intensive to feed one long strip into a machine that can automatically advance the film through and scan it one frame at a time, similar to the way a movie projector works, than to feed many separate shorter segments into a scanner. If your local drug store, such as Walgreens or CVS, no longer has a film mini-lab in store and they send the film out for processing they generally no longer send back the negatives with the prints and/or a data disc of digital images scanned from the negatives. If you are only getting scans and no prints, they may not send you anything physical at all. Instead they'll communicate an internet link from which you can download your scanned images.

You have other options than a local drug store regarding who does both the developing stage and the scanning stage. But regardless of who does it, both stages must be done for you to end up with a digital image file. You can't skip the developing stage even if all you want to end up with is a digital file.

You can do all of the developing yourself instead of outsourcing it to a drug store or dedicated photo lab. A wide variety of developing chemicals are available as is a wealth of information about how to use them. B&W developing is much simpler and less sensitive to temperature variations than color chemistry, so most people who develop their own film start out with B&W. Many develop their own B&W film but still outsource color development to a professional lab. Since it requires fewer processing steps and chemicals, developing B&W film is also cheaper than developing color film.

Once the film has been developed, either by a lab or by you, you can then decide who will scan it and how it will be scanned. You can use a scanner specifically made to scan film, you can use a flatbed scanner with a backlight attachment, or you can hire a commercial lab to scan it for you. Many commercial labs use much higher quality drum scanners than the typical scanners used at home by the do-it-yourselfer.

Keep in mind that due to the labor savings of doing both developing and scanning with automated machines in sequence before cutting and sleeving the negatives (or discarding them altogether), having previously developed negatives scanned later will often cost almost as much or even just as much as having them commercially developed and scanned by the lab all at the same time. Also keep in mind that the quality of scans from one lab to the next, and even one operator to the next on the same piece of equipment, can vary greatly depending on the equipment they use, how automated the process is, and how skilled and involved in the process the operator is.

Taking control of developing and scanning your own film gives you more control in determining what the final image looks like. Depending on where you live, it may be your only local option that lets you keep the negatives. But it also involves a significant investment of time to learn how to do either properly as well as money to purchase the needed equipment, chemicals, and supplies - not to mention a higher quality scanner. Ultimately you must decide if it is worth the extra time and cost¹ to gain that control.

¹ You'll never buy the chemicals, which have expiration dates, in large enough bulk quantities to get them for the same prices as large labs can. You'll probably also never utilize a very high quality scanner enough to lower the cost-per-image-scanned to that below the price that a lab will do it for you.