The "P number" refers to the distance in millimetres between LED pixels — a smaller number means a denser, sharper image at close range, but usually a higher cost per panel.
As a rule of thumb: P1.86 is built for viewers standing within a few metres — ideal for wall-mounted screens inside a shop, boutique or showroom. P2.5 is well suited to ticker bars and displays viewed from further back, such as above a counter or across a room, where the coarser pitch is imperceptible and the lower cost makes more sense.
Paying for finer pitch than your viewing distance requires is the most common overspend we see — tell us where people will actually be standing and we'll recommend accordingly, not just the more expensive option.