What is plane spotting?
Plane spotting is watching, photographing and identifying aircraft, usually from public ground near an airport or under a flight path.

At its simplest it's noticing what's overhead.
What do plane spotters log?
Many who stick with it go further and keep a record: the type, the registration painted on the airframe, where and when they saw it. Do that for a few years and you've built something that didn't exist before, and that record, rather than any single sighting, is usually what people mean when they say they are into it.
Logging or photography
Others treat it purely as photography. One quiet afternoon, one clean pass, decent light. Both approaches reward patience far more than they reward equipment. If you do want kit, the plane spotting equipment and apps guide compares apps, binoculars and cameras.
The etiquette, which matters
Stay on public ground, follow the signage, and don't photograph where it says not to. The goodwill that makes spotting easy depends on spotters behaving. It's a small thing to ask and it keeps the door open for whoever comes next.
Knowing the runway in use saves an entire wasted afternoon, and that comes straight out of what a runway is. Telling one family of aircraft from another is the types of aircraft. The settings and the standing-in-the-right-place part are in the plane spotting photography guide, one stage further along, and one airport's viewing places and rules are in plane spotting at Heathrow; Gatwick, Stansted and RAF Fairford have guides of their own. The places their operators publish across the rest of the UK are in plane spotting in the UK.
And once the photographs exist, they mostly sit on a drive. Your aircraft is the stage about doing something with them, and buying for somebody who spots is its own problem, covered in gifts for plane spotters. The rest of the reading is on the sky.
