that site is kinda confusing OTT with iptv because they are promoting their service. Both ott and iptv uses 'internet protocol' to serve content from server.
OTT - over the top like netflix (vod) , yupp tv , jio tv etc which is served through open server and does not involve isp.
IPTV - content from satellite is delivered to a centralized private server then served to customers using 'internet protocol' . in this setup centralized server is owned by isp so its like 'intranet' because you cannot access the server over internet. So isp do not have to pay anyone for bandwidth and its data should not be counted with FUP.
source: google
OTT - over the top like netflix (vod) , yupp tv , jio tv etc which is served through open server and does not involve isp.
IPTV - content from satellite is delivered to a centralized private server then served to customers using 'internet protocol' . in this setup centralized server is owned by isp so its like 'intranet' because you cannot access the server over internet. So isp do not have to pay anyone for bandwidth and its data should not be counted with FUP.
source: google