How can I choose between site technology and child domain for my far places in my Network?

It depends on the several factors whether you need single domain or multi-domain environment.
Once you are clear about your requirements, you can design your AD Infrastructure to contain domains, sites, subnets etc.
etc.
As the question is ambiguous, it is not possible to give detailed answer here.
Send me detail at my email address (), In shaa Allah, I'll send you the solution.

site is geographical but child is logical and u may have many sites with no child, also u may have child in the sale site.
child has nothing to do with site.
your far place is another site.
but it could be additional domain controller or child domain.
I suggest you use additional domain controller unless you want a sub domain like (subname.domainname.local) and install2 DCs in each site.

Hi actually to choose between having AD sites or AD child domains depend on how your organisation is , or how you want to manage the entire organisation.
Child domains can be a good aproache if you have logical non dependant / geographically separated entities that can be autonomous .or have differents buesness activities for example you can have one root domaine for Grooupe like GroupCompany.com with SwapFirm.GroupCompany.com , FoodFirm.GroupCoompany.com,ClothsFirm.groupCompany.com subdomaines .
AD site are more like logical optimisation to Active directory topology cross an AD forest .
i hope this help.

You should install a new Domain Controller on the other site, when these two domain controller will syncronize to one anothe then you can access all the child domain of each site.

i think when u promotion the server:and go start>>run>>dcpromo and select child from the setup wizard.

If your business or organization need to create security boundaries, then additional domains is what you choose. Do not forget that a domain is a security boundary with its own network resources such as users, computers, printers, GPOs,,..etc. For example, if your Finance department need resource separation from other departments, consider a new domain for the Finance department.

Again, it is all about security. Creating additional domains is a real headache to manage. I've dealt with many enterprises that use only ONE domain with several sites. Just use multi-domain if necessary and as per the business requirements.

 

The question is, what do you want to do exactly that made you ask this question? Give us more details about your considerations.

We make new site (that include ADC) if the second site will be managed by you and/or another  admin at the other site, in this case you  should have good WAN speed.

 

We make new child domain in case you want to seperate the management, security boundaries.