It's lower-level than C. The primitive datatypes, to the extent there are datatypes, are in terms of bytes and machine-words. Most Forths include a dialect for embedding machine instructions in word definitions.

It's higher-level than C. Forth allows you to layer on dialects with custom domain-specific syntax and do other kinds of fancy metaprogramming. You can use Forth to interactively extend itself while you're working. Many Forths include a "bootstrapping" script, written entirely in forth, which defines such niceties as control structures and the syntax for comments.