A rangefinder is in a priority mode if it reads only the first object in its view and ignores all other objects. It is in a second priority mode if it ignores the first object but sees beyond it to another object.
Priority differences
First priority rangefinders are extremely useful on the golf course. There is generally nothing between you and the flag, assuming the flag is not hidden. All rangefinders have the first priority mode. If you want to range at a flag located about 100 yards away, the flag will display 100 and not 130 which could be due to the trees behind the flag.
Second priority rangefinders can be more useful for hunting. A second priority rangefinder used as in the previous paragraph would certainly read the trees at 130 yards and ignore the flag 30 yards closer. Hunting situations often require you to be in a blind, or partially covered by leaves or limbs. The hunting rangefinder or second priority rangefinder would ignore any object within its line of sight, such as branches, and instead read the closest object, which could be a deer.
Can you use a golf rangefinder (first priority) for hunting? Absolutely. You can use a rangefinder (second preference) to play golf. Certainly. But the product most closely designed for your intended purpose would be more user-friendly and not require multiple readings or switching modes to ensure the correct distance. Some laser rangefinders offer options to temporarily switch from second priority mode with a "pinpoint" or "bullseye" button (effectively switching from second to first priority) or switching priorities semi permanently.
Distance
Rangefinders can be sold under names that indicate the maximum distance that the unit is capable of reading. This is the biggest misconception consumers have about these units. A unit may be labeled as a 1500 yard rangefinder, and it may be, but only under ideal atmospheric conditions on highly reflective large surfaces!
You may be able, for instance, to range a smooth, white metal pole barn at 1500 feet without too much glare, air pollution, heat waves, and heat waves, even if there is a lot more glare. If you add sun, rain, snow, heat mirage, or reduce the target's size, or darken or increase the color or texture, then NO! You may see hundreds of yards less. In perfect conditions you may see your pole barn at 1500 yards, a dark rocky hill at an oblique angle at 1100 yards, a huge truck at 900 yards, a tree at 700 yards, and a deer at 450 and a flag Visit This Link on the green at even less. Most times a deer may be read at around one third of the maximum stated range, and almost always well under half the distance. Check the manufacturer's specifications.
Reticles and Aiming points
A Reticule is the crosshair or aiming point/circle that you see in your rangefinder. Some reticles have black lines you can superimpose on the object you wish to range. These reticles are often impossible to distinguish against a dark background, or in low light conditions such as shadows. Some reticles (or aiming points or circles) appear illuminated because they are actually LED lights. These LEDs can be adjusted in brightness. The issues with LED reticles is that in bright conditions they may be drowned out by the ambient light so they cannot be seen, even at the highest settings, and in the evening, when your eyes are accustomed to the night, the reticles or circles are so bright that they destroy your night vision even at the lowest settings. The bright reticle is what blocks your vision. These issues are not limited to reticles. They also affect other information on your screen, such as yardage numbers or modes.
The best of both worlds, in my opinion, is a black reticle and information with a button for backlighting. Backlighting is less intense than an LED and allows you to see your information in any light condition.