===== PSS =====
The “proportional set size” (PSS) the tool smem reports is the memory the program plus the "fair share" of each shared area to give a realistic measure. At simpletools.info the PSS is the crucial criterion to determine the memory footprint of a program. The unit is **kilobyte (kB)**.


===== RSS =====
Most standard Unix memory tools are reporting the “resident set size” (RSS) - which roughly is the memory usage of a program plus the shared libraries it needs. Because it includes the whole shared memory it shares with other programs this isn't a fair representation of memory a program really needs. 

===== USS =====
The "unique set size" (USS) reports the memory needed by the program binary only, without any shared library it might need. This underestimates the programs memory footprint,unless it is a static linked binary. 


===== dynamic window manager =====
Dynamic window managers can dynamically switch between tiling or floating window layout. It means you can change the arrangement of windows at any time. 

There is a second definition in the context of tiling window managers:  A dynamic tiling window manager is a window manager where windows are tiled based on preset layouts between which the user can switch.

When we talk about "dynamic window managers" we mean the former