There are multiple ways to exchange data between your PC and an IBM i server. First, we need to distinguish different types of data:
a) simple text files for general purpose, or
b) objects like files, programs etc.
a simple text file can be quickly transferred using FTP into the integrated filesystem on IBM i - primarily to your homedirectory at /home/yourname. Objects (mostly packed in a save file) should be transferred into one of your libraries to retain integrity and to be able to use them. Then it comes to special name format and how to address your library...
Let us assume your first library is named "yourname1", then the IFS (integrated file system) on IBM i does address this as /QSYS.LIB/YOURNAME1.LIB - because library YOURNAME1 is contained within the QSYS library.
Let us also assume, you have a savefile named EXPPGM which contains some objects like sourcecode and programs on your PC. Hopefully, your file does have an extension, so the full name should be EXPPGM.SAVF - if not, please change the name now, as this will make life more easy! :-)
Now you connect to PUB400.COM using your favorite FTP client. There are numerous, depending on your client operating system. Some behave different as they assume you connect to a linux server which uses some varying directory name format, which can be confusing on IBM i. After you connect and enter your user name and password, pay attention!
The first command of your FTP client should be "cd" (change directory) to the target directory on PUB400. If you want to transfer some text files to your home directory, your client sould issue:
cd /home/yourname
If you have a save file (like EXPPGM.SAVF) which should be transferred to your first library, the FTP client must issue:
cd /qsys.lib/yourname1.lib
Then choose ascii or binary transfer (the latter one os a must for save files) to transfer.
If you transferred to your home directory, you can use ssh to work with the contents, or use command WRKLNK on green screen. There will be articles on several commands, so do not worry, or ask google :)
If you transferred a save file to your library "yourname1", use the following command to check if transfer was ok:
DSPSAVF YOURNAME1/EXPPGM
System should show some information about the save file and its contents.
