This document discusses third and fourth generation programming languages. Third generation languages (3GLs) are machine-independent and can be compiled to run on many devices. Some early 3GLs from the 1950s include FORTRAN, ALGOL, and COBOL. High-level languages can be either compiled or interpreted. Fourth generation languages (4GLs) use more human-like statements and require less coding than lower-level languages. Examples of 4GLs include Perl, PHP, Python, Ruby, and SQL. 4GLs offer advantages like easier learning, maintenance, and development speed, while sometimes suffering from slower execution speed and increased memory usage.