Shinobi headbands, also known as forehead protectors, are surprisingly important in the world of Naruto. Each one signifies loyalty to the ninja village they represent, which is why when a ninja decides to defect from their village, they sometimes scratch a line through the symbol they used to protect.
Naruto headband symbol meanings can be subtle, like Sunagakure's use of a stylized hourglass to indicate its name, the Village Hidden in Sand. Others are more straightforward, like Iwagakure's symbol, which is two rocks.
All of these forehead protectors are deeply important to those who wear them, but all are not equal for the anime's fans. Which are the best Naruto headbands? That's up to you.
When a ninja defects from their home village, they may continue to wear their old forehead protector, but scratch out the symbol of that village to indicate that they are no longer a part of it. Missing-nin, as defectors are called, make no attempt to hide their histories, and in fact may wish to show disdain for their village of origin. All members of the Akatsuki wear forehead protectors like this.
The Leaf headband is probably the best-known one in the Naruto series. It bears the symbol of the Village Hidden in the Leaf, also known as Konoha, which is where the protagonist, Naruto, hails from.
Jiraiya is actually from Konoha, and originally served as a ninja of that village. While he hasn't defected, he chooses to wear the word "oil" which symbolizes the time he spent training at Mt. Myōboku. While the exact reason for this is never made clear, Andy Lee Chaisiri of Quora believes that it may be because, during his frequent travels, he isn't traveling as a ninja, he's traveling as a sage, and he wishes to be able to get along with people who might have problems with his home country.
During the Fourth Shinobi World War, the Akatsuki and the Tailed Beasts were too powerful for any one nation to take on alone, so the Lands of Lightning, Water, Earth, Wind, and Fire joined forces with the Land of Iron, a samurai nation, to create the Allied Shinobi Forces. The character on the forehead protector simply means "shinobi" implying that what's important is not what separates them, but what they have in common. They are all warriors fighting for the greater good.