A B-tree is a self-balancing m-way search tree structure engineered to optimize disk and block storage system access patterns. Internal nodes contain between ⌈m/2⌉ and m children, holding sorted key sequences that segment search subspaces across multi-branch pointers. When insertions cause nodes to overflow maximum key limits, the median key ascends to the parent while the remaining keys split into two balanced sibling nodes, preserving uniform logarithmic depth.