Arguably the most significant aspect to the Browning Hi Power, aside from the double-stack magazine, is the locking mechanism.
Modern semi-automatic pistols use a locked-breech system, wherein a sliding assembly and the barrel completely lock in place when the pistol is in battery. When the pistol is fired, the barrel is driven backwards under recoil along with the slide, much like the bolt on a semi-automatic rifle. To keep pistols from being unnecessarily large, handguns are made to use a short recoil system, which decreases the distance the bolt/slide and barrel must travel.
The previously dominant short-recoil system that didn’t involved a fixed barrel (which, such as in the case of the Walther PPK, is literally pinned in place) was the tilting link of the M1911, which – by virtue of the tilting link of the barrel – tilts after a short travel and lets the barrel pivot slightly upward, unlocking the action until the slide returns to battery.
Since the barrel has to stop short compared to the slide, a camming action is therefore necessary.
When Browning was designing the 1911 in the early 1920s, he couldn’t use a tilting link as the M1911 pistol was still the intellectual property of Colt. He came up with a new design, with a block that allowed the barrel to tilt in the same manner but without requiring a toggle link.
The barrel block also includes a feed ramp, as the feed ramp likewise could not be integral to the frame since that was a design element of the 1911 pistol.
Today, virtually every popular handgun on the market regardless of the firing mechanism (striker, single-action, double-action, what have you) uses the Browning linkless falling block, which functions as a linkless cam. In fact, a Glock barrel’s locking block is barely any different.
There are exceptions; Beretta 92 series pistols use a locking wedge (taken from the Walther P38) and the Beretta PX4 Storm series of pistols use a rotating barrel, which cams in place by rotating along the Z axis (front to back in three-dimensional space) instead of the X and Y (left/right, up/down) axes. With that said, the Browning linkless barrel block is basically the default pistol barrel design to this day.