Minecraft Education Edition offers a wide range of tools that allow educators to limit the game world of their students. The border block is the most visible and easily distinguishable tool.
Border blocks stop entities from moving beyond, below, or through the block. This effectively creates a barrier that restricts players and other entities to a specific area. These blocks can only be accessed via the command console, or by selecting the block from the Creative Mode inventory. They are not breakable by fire, explosives, or tools, so they operate like a hitbox.
Border blocks are a great way to create controlled environments for educators and curious Minecraft players. Border blocks create an indefinite height barrier above and beneath them (not sideways; however, the blocks must be connected together to form an effective enclosure). This can be impossible to overcome for students or players without worldbuilder permissions.
The border block's barrier also stops players from moving, so most mobs can't pass it. However, some Minecraft entities, such as the Ender Dragon, can pass through, and things like projectiles or explosions can still get through a barrier. While this may pose problems for educators or prospective players, it should not be a problem for entities that are inside.
If Minecraft Bedrock Edition is enabled within the world settings, border blocks can be used in Minecraft Bedrock Edition. Although Minecraft Education Edition features can be accessed, some may not work as expected due to software or peripheral support (mostly those involving programming code like the Agent mob). The border block should work as expected. Players without Education Edition will still be able to enjoy some of the block's capabilities if they have Bedrock Edition.