RPG (Report Program Generator) is a high-level programming language primarily used for business applications. It was developed by IBM in the 1960s and has evolved significantly over the decades. RPG is known for its strong integration with IBM's midrange systems, particularly the IBM i (formerly known as AS/400, iSeries, and System i).

1. Business-Oriented: RPG is designed specifically for business applications, making it highly efficient for tasks such as data processing, report generation, and database management.
2. Fixed-Format and Free-Format: RPG originally used a fixed-format syntax, but modern versions support free-format coding, which is more flexible and easier to read.
3. Integrated with IBM i: RPG is tightly integrated with the IBM i operating system, providing seamless access to its powerful database and system functions.
4. Procedural and Modular: RPG supports both procedural and modular programming paradigms, allowing developers to write reusable and maintainable code.

1. Legacy Systems: Many businesses still rely on legacy systems running RPG applications. Learning RPG can open up opportunities to maintain and modernize these systems.
2. High Demand: There is a high demand for RPG developers, especially in industries such as finance, manufacturing, and logistics.
3. Powerful Integration: RPG's integration with IBM i makes it a powerful tool for developing robust and efficient business applications.
4. Career Advancement: Mastering RPG can lead to career advancement opportunities, including roles in system administration, application development, and IT management.

Let's look at a simple RPG program to understand its basic structure.

1. Dcl-S: This statement declares a variable. In this case, message is a character string with a length of 50, initialized to 'Hello, RPG World!'.
2. Dsply: This command displays the value of the message variable on the screen.
3. *Inlr = *On: This statement indicates the end of the program. It sets the last record indicator to on, which tells the system to close files and release resources.

In this section, we introduced RPG, a high-level programming language designed for business applications. We discussed its key characteristics, evolution, and reasons to learn RPG. We also provided a simple example to illustrate the basic structure of an RPG program. In the next section, we will guide you through setting up your development environment to start coding in RPG.