Online Algorithm
Domain: Algorithms
🎯 Motivation
An algorithm that processes input piece by piece as it arrives, without knowing the future. Must make decisions with partial information.
📋 Concrete Example
LRU cache is online: it must decide what to evict as requests arrive, without knowing future requests. Insertion sort is online: it sorts as elements arrive one by one.
🔗 Analogy
A goalkeeper in football: they must react to each shot as it comes, without knowing where the next shot will go. They cannot see the future; they must decide with current information.