1. Four generations of Programming Language:
1st: machine code—binary streams: CPU can only understand this
2nd: assembly—readable codes: understandable, small obj size, still relevant at present
3rd: procedural: loop/recursion, condition, sequential
3 programming paradigms, some unique feature of functional programming: function is 1st class object, no side effect, lazy evals, etc., whose renewed popularity by big data.

2. procedural: 3 types C(2.5)/Cobol/pascal: wirth, Dijkstra/Pascal 4th: OO: java 95% inheritance: reuse, localize, DB: SQL-like: declarative (prolog) SQL: DB based what to do; all other: how 3 prog. Paradigm: functional, imperative(default), logical ( prolog) 4GL functional programming: Haskell/scala: no side effects, lazy: eager, first-class object (short) life cycle models: steps to be taken in system dev. (in)feasible: early 60s, MIT: computer vision as a course project, security system: replace guards: compare human face vs id photo