请解释一下EC和ECDIS.请用英文

EC:means Electronic chart,and ECDIS MEANS Electronic chart diaplay and information system.this system uses the coputer technology to provide chart details on a visual display unit,combined woth an automatic indication of ship,s position.and possibly a radaar image,and a navigation aide,this kind od chart need basic computer operation skills and automation knowledge

EC=European Community 欧洲共同体
ECDIS=Electronic Chart Display and Information System电子海图显示和信息系统