Foundation-anchor-bolts vary in design, function/use, materials, size, & spacing;
the requirements are specified by your-local-building-codes
(for-instance, earthquake/seismic-zones require larger-sizes and/or tighter-spacing).
Common-sizes range from about 1/2" by 6" to (2" to 4") by 36".
Foundation-anchor-bolts usually anchor wood-sills to your-foundation;
they can also be used to anchor walls to soils.