7 mode Netapp configuration supports flat command line interface, whereas Netapp cluster mode supports the hierarchal cmnd line interface, Read a post.
There are some major differences between clustered Data ONTAP configurations and the configurations, operating with Data ONTAP in 7-Mode. In the clustered data ONTAP, the cluster configuration contains two HA pairs, with each HA in a separate cluster and at physically different sites.
While, the number of storage controllers is 4 in clustered mode, there are two storage controllers in 7 Mode. In case of the clustered configuration, the controllers are configured as two different HA pairs, with one on each site. In case of the 7 Mode, two controllers are configured as a single HA pair, with one controller at each site. For more info read a post.