pls explain about db00 processes

Hello,

I understand that dw00 dw01 are for expdp processes and what does db00 mean?

[amdc-oragrid-ux04]sgraph_01(P):/prodoragridcn_01/app/oracle> ps -ef|grep -i d|grep -i sgraph

  oracle  8585362        1   0   Apr 19      - 68:25 ora_diag_sgraph_01

  oracle 11862050        1   0   Apr 19      - 41:56 ora_dbw0_sgraph_01

  oracle 30277772        1  14 15:33:54      -  0:55 ora_dw02_sgraph_01

  oracle 40173746        1   0   Jun 30      -  0:00 oraclesgraph_01 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))

  oracle 43122740        1   0   Jun 30      -  0:01 oraclesgraph_01 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))

  oracle 44498968        1  30 15:16:48      -  1:24 ora_dw01_sgraph_01

  oracle  4129132        1   1   Apr 19      - 254:27 ora_lmd0_sgraph_01

  oracle  4719004        1   0   Apr 19      -  4:42 ora_dbrm_sgraph_01

  oracle  4850104        1   0   Apr 19      - 448:54 ora_dia0_sgraph_01

  oracle 15532298        1   0 15:16:46      -  0:01 ora_dm03_sgraph_01

  oracle 23068988        1   1 15:04:51      -  0:01 ora_dm00_sgraph_01

  oracle 26870142        1  23 15:04:55      -  1:46 ora_dw00_sgraph_01