Sqlplus.exe and sqlplusw.exe are the conventional interfaces used to query against the Oracle Database.iSqlPlus is the browser based interface that doesnt require any installation on the machien to query the database.To know the port numbers at which isqlplus and Enterprise Manager Console are running look into the portList.ini file located in ..\db_1\install folder.
For example
iSQL*Plus HTTP port number =5560
Enterprise Manager Console HTTP Port (orcl) = 1158
Enterprise Manager Agent Port (orcl) = 3938
Here isqlplus runs at 5560.To acces it.. http://OracleServerMachienName:5560/isqlplus
If this doesnt work check if the isqlplus service is Up under the Windows Services[Services.msc]
For example
iSQL*Plus HTTP port number =5560
Enterprise Manager Console HTTP Port (orcl) = 1158
Enterprise Manager Agent Port (orcl) = 3938
Here isqlplus runs at 5560.To acces it.. http://OracleServerMachienName
If this doesnt work check if the isqlplus service is Up under the Windows Services[Services.msc]