The build in the first link is... strange. I'm not sure what its purpose is, but I don't think it out-performs other proper Holy talent builds. The second one is also a little bit odd, since it looks like it's trying to be a Renew build, but it's picking up Seredipity (which is less useful for Renew gameplay) and leaving out Test of Faith (which is stronger than Seredipity for the Renew-spam play-style).
There are 3 proper Holy builds. Variation is up to personal preference at points, but I'll briefly explain what each are for without writing a novel.
1. Low gear spec.
This build assumes your gear is terrible and that you would be doing content appropriate for that gear (5 and 10-man content).
Renew is less of a priority spell, and usually something you'll only use on a tank or someone that is taking constant damage. Most of the time, you will be casting direct heals; such as Flash Heal to build Seredipity stacks, then Greater Heal when you need to nuke heal (often on the tank).
http://wotlk.openwow.com/talent#bVcbuZdxtccMVih0euio
2. 5-man dungeon & 10-man raid spec.
This build is intended to be versatile. Points can be taken from talents that boost things you feel you don't use to invest in mana efficiency if necessary. If you are geared, this shouldn't be necessary. This build allows you to nuke & flash heal when necessary, but also capable of group-healing and utilizing Renew at its full strength.
http://wotlk.openwow.com/talent#bVcbuZfvzcb0VihoeuAo
3. 25-man raid "Renew spec".
This build focuses on the healing of large groups. You will find yourself regularly using Renew and using Circle of Healing & Prayer of Mending usually on cooldown. This spec can also make effective use of Prayer of Healing when you need to help heal entire groups through periods of large damage. Seredipity isn't take because it requires you to Flash Heal or Binding Heal to utilize it. These aren't things you will be doing when performing this role, especially without having the talent "Surge of Light". Those points were taken and invested in Blessed Resilience instead, since it provides a flat healing increase. Healing Focus is considered a "filler talent" due to this build largely relying on instant cast spells. It is better to put this point here than in Divine Fury, since you will never use Greater Heal with this build, but the pushback resistance can be useful when casting Prayer of Healing.
https://wotlk.evowow.com/?talent#bVsbu0hZsEzcbMVVhG0uAo
Spirit of Redemption.
This is a preference talent. If you never die, you will never utilize it. However, if you or the group you are playing with are doing progression into difficult content, then you can consider taking it. For farm content, ithe angel portion is largely useless. The exception to all of this being the 5% spirit it grants which is worth both some regen and some spell power. All things should be considered before deciding to take or not to take it.
Lightwell.
Great spell, except that nobody ever clicks it. Therefore, useless.
Sorry for the wall of text, but I hope you find this useful.