Typically, the terms 'transit' and 'peering' are used when routes are exchanged via BGP between ASNs.
If i subscribed to an ISP internet service and the IP range is allocated by the ISP - it is consider IP transit right ?
Usually, no, not unless you're exchanging routing information via BGP. If not, it would just be 'internet access'.
If i have an ASN number / owned and subscribed IP range from APNIC and i want to advertise this IP range through 2 different ISP provider - is this still consider IP transit ?
IP transit refers to the routes exchanged. If you buy IP transit from an ISP, you get all routes in the DFZ (Default Free Zone), so you can reach the entire internet.
If i have an ASN number / owned and subscribed IP range from APNIC and directly connected to an IX service - this will then be consider IP peering ?
Yes, if you setup BGP sessions with other networks at the IXP. With peering, you typically receive only routes to the peer's network and its downstreams. So unless you peer with every network (or an upstream of every network), you won't reach every network on the internet.
Why will one choose 3) over 2) ?
You don't, not unless you're a Tier 1 network. Only those networks are big enough to receive a full view of the DFZ via peering sessions.
Any other network needs transit to reach specific parts of the internet. It's impossible to receive a full routing table via peering otherwise.
You can add peering to IXP's for various reasons, for example to reduce latency, lower costs or reduce dependency on specific transits.
