The real deal
SOOC is simply an abbreviation meaning Straight Out of Camera in relation to digital photography. It signals that the image has not been edited in any way and is as close to the original as you can get.
Many think of SOOC as meaning no editing in software designed for the purpose like Lightroom or Photoshop. However, most cameras allow a profile to be applied to the image (standard, vivid, B&W, vintage, etc) and then it is debatable how unedited the image actually is. From the camera picks up the information from the sensor and until the information is written to the memory card, there is a bit of processing going on, so the completely unedited image is probably difficult to find.
The closest is a RAW image format, but even here the ISO settings influence the processing of the image. Many think that the ISO setting influences the sensors sensitivity to light, but the sensors sensitivity is constant. Instead the ISO settings governs a gain applied to the light readings from the sensor, and this camera internal processing can – with a bit of good will – also be seen as a sort of editing.
So I see SOOC more as an ideal that some like to get as close to as practically possible. Many professionals do what they can to get the images right in camera i.e. make sure the framing is spot on and no tweaking to e.g. the exposure settings is necessary in post to make the images look their best. They do not do so out of idealism, but simply because it saves time, and as you know: time is money. A school photographer taking several thousands of headshots over a year can save a lot of time if there is no editing needed but the result can be printed and delivered to the clients as is.
So my advice is that you should not put too much into the SOOC term. See it as an ideal and just know that when a camera reviewer says he /she presents the images SOOC, it is just another way of saying that the images could probably be even better with a bit of time spent editing.