MT4 gives automated trading a practical home. MetaQuotes says the platform lets you develop, test, and apply Expert Advisors and technical indicators, with MetaEditor for building them and a Strategy Tester for testing or optimizing them before live use. Its own help pages define Expert Advisors as MQL4 programs that automate analytical and trading processes, perform technical analysis, and manage trades from signals. Strip away the jargon and the idea is plain enough.