Mathematics is divided into 2 major branches:

1. **Analysis** (Continuity, alculus)

2. **Algebra** (Set, Discrete numbers, Structure)

In between the two branches, **Poincaré** invented in 1900s the **Topology (拓扑学)** – which studies the ‘holes’ (disconnected) in-between, or ‘neighborhood’.

Topology specialised in

– ‘local knowledge’ = **Point-Set Topology**.

– ”global knowledge’ = **Algebraic Topology**.

__Example:__

The local data of consumer behavior uses ‘Point-Set Topology’; the global one is ‘BIG Data’ using Algebraic Topology.