You have asked abt so many things ...
1. OOPS
In software OOPS means
Object Oriented Programming and Systems.Here elements are generated once and they are thought to be objects in the submodules and there refernces are generated for multiple uses in the main module .
2. LINUX
This is a free open source UNIX type but enhanced Graphics with Text command applicable Operating System.Linux's kernel (the central part of the operating system) was developed by Linus Torvalds at the University of Helsinki in Finland
3. Thin Client
I am Not sure , but what I came to know is -the term thin client usually refers to software, it is increasingly used for computers, such as network computers and Net PCs, that are designed to serve as the clients for client/server architectures. A thin client is a network computer without a hard disk drive, whereas a fat client includes a disk drive
4. OPEN SRC
It is having some characteristics , please check the link -
https://www.opensource.org/docs/osd
Next time I will give the answer to left points.... as i got busy now ....
bye.......