What is Cypher and how does it query graphs?

Cypher is Neo4j's declarative graph query language. It uses ASCII-art notation to express graph patterns. Key syntax: (node) represents a node. -[:RELATIONSHIP]-> represents a directed relationship. (a)-[:KNOWS]->(b) matches node a connected to node b via KNOWS relationship. Filtering: WHERE a.age > 25. Variable hop: -[:KNOWS*2..4]-> matches 2 to 4 hops. Pattern: MATCH (alice:Person {name:'Alice'}