meaning of a pacKage

[Altera_Forum]

1)i dont understand the meaning of this package:  

package body dwt2dpkg is     function dwt2dctrlvector(x : in type_dwt2d_ctrl_signal_enum) return type_dwt2d_ctrl_signal is   begin   return type_dwt2d_ctrl_signal(to_unsigned(type_dwt2d_ctrl_signal_enum'pos(x), cst_dwt2d_ctrl_sig_bus_width));   end;    end dwt2dpkg;:confused::eek: 2)i dont understand the utility of this code:   type type_dwt2d_state is (  ts2d_ready,  ts2d_init_horiz,  ts2d_start_horiz,  ts2d_continue_horiz,  ts2d_init_vert,  ts2d_start_vert,  ts2d_continue_vert,  ts2d_next_level,  ts2d_terminate  );:confused::confused:   can any one explain it to me. Thinks

[Altera_Forum]

Package is a support vhdl program that is not meant to be a module like other design module but to insert any constants, functions in a neat way. It is optional. Most people use one package per project to insert their constants and functions. Others go as far as one package per module...too excessive. 

  type my_states is (s0, s1,s2....etc); signal state : my_states;  means you create your own type, meaning a replacement for vhdl own types like std_logic etc. in order to help readability. For example it is convenient to use s0,s1,s2 than explicit binary value. The compiler then is free to encode the states.