Internet website design, programming, management and maintenance; computer software design, programming and maintenance; database preparation; recovery of computer software; updating of computer software; maintenance and management of computer systems; on-line providing of computer programs; leasing of on-line access time to a computer network, consultancy on computer software designing, technical information relating to computer software and hardware; introduction and explanation of performance, operation, etc of computers, automobiles and other machines which require high level of operators' knowledge, technique and/or experience for accurate operation of them