Many article titles are disambiguated with parenthetic qualifiers, like this: [[Self (psychology)]]. But when you want to include such a link in the body of an article, this would look rather awkward. So all you have to do is use the "pipe trick", like this: [[Self (psychology)|]]. Notice the "|" character stuck in there at the end of the link? That makes the link look like this: Self, without having to type the name of the link after the pipe!
This trick also works with namespaces, so that [[Wikipedia:Tip of the day|]] (again notice the pipe character) displays like this: Tip of the day.
Salisbury Cathedral is a Church of England cathedral in the city of Salisbury in Wiltshire, England. It was built between 1220 and 1258 in Early English Gothic style. This photograph, taken in 2014, shows the interior of Salisbury Cathedral, looking eastwards towards the high altar through the tall and narrow nave. It has three levels: a tall pointed arcade, an open gallery, and a small clerestory. The nave includes an unconventional modern baptismal font, installed in September 2008. Designed by the water sculptor William Pye, it is the largest working font in any British cathedral. The font is cruciform in shape, and has a 10-foot-wide (3.0 m) vessel filled to its brim with water, designed so that the water overflows in filaments through each corner into bronze gratings embedded in the cathedral's stone floor.