World Anchor and and Chunk Loader are in fact two different chunk loading options in the pack.http://feed-the-beast.wikia.com/wiki/World_Anchor
A "world anchor" is just another name for a chunk loader. Although the world anchor can be placed into a cart, which could be useful, but they require fuel. You should review the ChickenChunk chunkloader (http://feed-the-beast.wikia.com/wiki/ChickenChunks).
World Anchor is a chunk loader that has a 3x3 size and runs on ender pearls. 12 hours per pearl and can be disabled with redstone.
World anchor can be combined with an anchor sentinal to change the 3x3 shape in to a line. I believe it is up to 9 chunks in a line.
Anchors are added by railcraft, so if you use them you can read up more on the RC wiki.
Chunk Loader is added by ChickenChunks mod. They can be controlled by redstone and have no fuel cost. Right click the Loader to customize its shape and size and it has a laser mode to show the area loaded. A radius of up to 10x10 can be loaded by it.
The chunk loader can also be crafted into 10 spot loaders. Each spot loader keeps the chunk its in loaded, no GUI/options on it -- also it does not seem to respond to redstone. These are new to the mod though and might get that feature in a newer version.