2. Device memory can be used to store media; system is where files are stored for applications, messages and contacts i.e. the databases are stored.
DEvice memory is 1GB.
System memory is 128MB. otherwise known as Application memory.
3. Yes, it would be used to load and run apps. hence why running app world decreases the app memory free.
"That's it then. Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings... and call off Christmas."