Replication Service: SQL Server 2000 replication enables sites to maintain multiple copies of data on different computers, in order to improve overall system performance, while ensuring that all the different copies are kept synchronized. DTS: By using DTS, you can build data warehouses and data marts in SQL Server by importing and transferring data from multiple heterogeneous sources interactively or automatically on a regularly scheduled basis. Analysis Services: Analysis Services provides tools for analyzing the data stored in data warehouses and data marts. Metadata services: SQL Server Meta Data Services provides a way to store and manage metadata about information systems and applications. This technology serves as a hub for data and component definitions, development and deployment models, reusable software components, and data warehousing descriptions. Reporting services: used to generate reports from the data in the database

Window a windows NT user account with administrator privileges,SQL Server cannot schedule task  and alerts, or perform replication.

Active Directory (AD) sites, which consist of well-connected networks defined by IP subnets that help define
the physical structure of your AD, give you much better control over replication traffic and authentication traffic than the control you get with Windows NT 4.0 domains.
Because AD relies on IP, all LAN segments should have a defined IP subnet. This makes creating your AD site structure straightforward; you simply group well-connected subnets to form a site.

Creating AD sites benefits you in several ways, the first of which is that creating these sites lets you control
replication traffic over WAN links. This control is important in Windows 2000 because any Win2K domain
controller (DC) can originate changes to AD. To ensure that a change you make on one DC propagates to all DCs, Win2K uses multimaster replication (instead of the single-master replication that NT 4.0 uses). You might think that multimaster replication would make it difficult to plan for AD replication's effect on your WAN links, but you can overcome this obstacle using AD sites.

Replication is a method of copying data from one database to other database or one server to another .
We have different  types replications.
Transactional , Snapshot , Merge , Logshipping and in 2005 one more type is introducde which was called as peer to peer replications.
Transactional Replication In transactional replication data is copied first time as in snapshot replication , but later only the transactions are synchronized rather than replicating the whole database.You can either specify to run continuously or on periodic basis.
Snapshot Replication takes snapshot of one database and moves it to the other database.After initial load data can be refreshed periodically.The only disadvantage of this type of replication is that all data has to copied
each time the table is refreshed.
Merge replication combines data from multiple sources into a single central database.Again as usual the initial
load is like snapshot but later it allows change of data both on subscriber and publisher , later when they come on-line it detects and  combines them and updates accordingly.

There are lots of options available, you have to choose your option depending upon your requirements.
Some of the options you have are: BACKUP/RESTORE, dettaching and attaching databases, replication,
DTS, BCP, logshipping, INSERT...SELECT, SELECT...INTO, creating INSERT scripts to generate data.

Use Replication of data in distributed environment.
Use the snapshots to replicate data.
Use the remote procedure calls.