Everyone knows how to use a plectrum - you drag the pointy end across the strings... right...?
Wrong....
The plectrum is a part of the tone mechanism of your guitar - and you can get some variety in your sound by how you use your plectrum.
The traditional pointed end gives you a medium tone... but when you look at a plectrun, you realise that it has three corners and 3 sides - usually.
The more rounded the point you use on the strings, the more mellow the tone you get - so we try to have at least two and sometimes three distinct points for you to play with - a standard point, a rounded point - and on the sharkfin plectrums - a really sharp point - all for the sake of tone.
Now - it gets interesting....
You can also use the sides of the plectrum as well!
The plain edge will give a brighter, 'shimmering' sound which is quite pleasant... and then there's the other side - the notched side.
the notched side gives you the effect of hitting the string multiple times, in quick succession, and that gives you a very bright tone because of the complex string vibration. It's similar to - but not quite like - a 12 string sound... and it's louder!