Answer to Question 1
Because the SDLC takes so long and is so expensive to use for developing information systems, much effort has been spent on trying to develop alternative methodologies. The most popular one is the idea of prototyping. The main idea is to get a working prototype of the system into the users hands as soon as possible in order to get their feedback on it. This then is iteratively refined. For smaller projects, training the users on the basics of software development and tools gives them the option of developing the applications themselves. This is also called the end-user development approach but it is only good for smaller applications.
Answer to Question 2
A database is a structured collection of related data stored on a computer medium. The purpose of a database is to organize the data in a way that facilitates straightforward access to the information captured in the data.
