Just like most software, Breath of the Wild requires non-executable content files to work correctly. They are stored in the title content directory on Wii U and in the romfs on Switch.
To minimise loading times, files that are frequently loaded together or at the same time are packed into SARC archives. Because of this optimisation, a significant amount of game files are located within archives. Some files may also be present in more than a single archive with the same resource path.
Actor contains files defining actors.
The Event directory contains files defining in-game events.
The Layout directory contains sblarc layout archive files for the game's GUI and HUD. These are used to store UI files (layouts, animations and images).
The Local directory appears to be a development remnant. It is unused in release versions and is not present at all on Switch.
Map contains files defining the game's map areas and the objects that populate them.
Model contains sbfres graphic resource files, which contain models, textures and animations. Sometimes a texture or animation file will be in the unpacked content files, but its corresponding model will be inside an archive.
Movie contains pre-rendered cutscene videos.
NavMesh contains shknm2 navigation mesh files, used to determine where enemies and NPCs can walk in order to control their AI.
Pack contains SARC archives which contain other files, in order to minimise loading times.
Physics contains Havok physics files.
Sound contains audio files.
The Terrain directory contains files defining the game world's terrain.
UI contains files used by the game's HUD and GUI.
The Voice directory contains voice acting audio files.
These content directories only exist inside SARC archives, and are not in the unpacked content files.
The Chemical directory contains configuration files for the game's chemistry engine.
The Demo directory contains cutscene configuration files.
The Ecosystem directory contains configuration files for game areas, and for the Placement and AutoPlacement systems (which statically or dynamically spawn actors).
The ELink2 directory contains configuration files for the game's effect link (ELink) system.
The Env directory contains environment files.
The EventFlow directory contains files defining in-game events and cutscenes.
The Message directory contains the game's text files.
The Mii directory contains files relating to the UMii system for constructing NPC models from parts.
The Shader directory contains game shader files.
The SLink2 directory contains files relating to the game's SLink sound link system.
The Tips directory contains configuration settings for the game's loading screen hint messages.
Contains overworld climate and environment parameters.