The idea of 4GL is start in 1980, to have very high level language which help user to build their own application. In fact its not really a software methodology, but its an approach to use high level technology.
4GL (Fourth generation language), are programming languages which are close to human language. Best example for 4GL are database languages. Its very similar to human language as you know, to make it clear lets look at one example:
select name from table where ID = ‘1000’
If you look carefully you will see the similarity to daily conversation. Its very easy to understand and even non-programmer can understand whats going on.
4GL is a high level language with specific programming purpose, for example developing business-oriented, database-centric systems.
Its nice idea to have such advance language, perhaps some day we reach that point but currently, the goal of ” high level language which help user to build their own application ” is not yet achieved.