Most offerings have an effective range within which the offering can be closed out and deemed a success by the Company. The minimum and maximum offering amounts are what set this range - these figures are set by the company and vary depending on the transaction.
The holding account will hold all investor funds up until such time as the minimum offering amount has been reached. Then all funds can be transferred to the corporate operating account of the company and are available for use by the company.
The account can be a managed escrow account or just a separate bank account managed by the company.