diff --git a/crates/ra_analysis/src/completion/mod.rs b/crates/ra_analysis/src/completion/mod.rs
index 5ef278127e..1eb804c855 100644
--- a/crates/ra_analysis/src/completion/mod.rs
+++ b/crates/ra_analysis/src/completion/mod.rs
@@ -11,7 +11,7 @@ use rustc_hash::{FxHashMap};
 
 use crate::{
     db::{self, SyntaxDatabase},
-    descriptors::{
+    hir::{
         module::{ModuleDescriptor}
     },
     Cancelable, FilePosition
diff --git a/crates/ra_analysis/src/completion/reference_completion.rs b/crates/ra_analysis/src/completion/reference_completion.rs
index 858b52e76e..ac6ef1d4a7 100644
--- a/crates/ra_analysis/src/completion/reference_completion.rs
+++ b/crates/ra_analysis/src/completion/reference_completion.rs
@@ -10,7 +10,7 @@ use ra_syntax::{
 use crate::{
     db::RootDatabase,
     completion::CompletionItem,
-    descriptors::{
+    hir::{
         module::{ModuleDescriptor},
         function::FnScopes,
         Def,
diff --git a/crates/ra_analysis/src/db.rs b/crates/ra_analysis/src/db.rs
index 4e34265fbc..fa59b8b3ea 100644
--- a/crates/ra_analysis/src/db.rs
+++ b/crates/ra_analysis/src/db.rs
@@ -7,7 +7,7 @@ use salsa::{self, Database};
 
 use crate::{
     db,
-    descriptors,
+    hir,
     symbol_index::SymbolIndex,
     syntax_ptr::SyntaxPtr,
     loc2id::{IdMaps, IdDatabase},
@@ -122,15 +122,15 @@ salsa::database_storage! {
             fn file_symbols() for FileSymbolsQuery;
             fn resolve_syntax_ptr() for ResolveSyntaxPtrQuery;
         }
-        impl descriptors::DescriptorDatabase {
-            fn module_tree() for descriptors::ModuleTreeQuery;
-            fn fn_scopes() for descriptors::FnScopesQuery;
-            fn _file_items() for descriptors::FileItemsQuery;
-            fn _file_item() for descriptors::FileItemQuery;
-            fn _input_module_items() for descriptors::InputModuleItemsQuery;
-            fn _item_map() for descriptors::ItemMapQuery;
-            fn _fn_syntax() for descriptors::FnSyntaxQuery;
-            fn _submodules() for descriptors::SubmodulesQuery;
+        impl hir::DescriptorDatabase {
+            fn module_tree() for hir::ModuleTreeQuery;
+            fn fn_scopes() for hir::FnScopesQuery;
+            fn _file_items() for hir::FileItemsQuery;
+            fn _file_item() for hir::FileItemQuery;
+            fn _input_module_items() for hir::InputModuleItemsQuery;
+            fn _item_map() for hir::ItemMapQuery;
+            fn _fn_syntax() for hir::FnSyntaxQuery;
+            fn _submodules() for hir::SubmodulesQuery;
         }
     }
 }
diff --git a/crates/ra_analysis/src/descriptors/function/imp.rs b/crates/ra_analysis/src/hir/function/imp.rs
similarity index 95%
rename from crates/ra_analysis/src/descriptors/function/imp.rs
rename to crates/ra_analysis/src/hir/function/imp.rs
index e09deba0f3..cd573a47f3 100644
--- a/crates/ra_analysis/src/descriptors/function/imp.rs
+++ b/crates/ra_analysis/src/hir/function/imp.rs
@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use ra_syntax::ast::{AstNode, FnDef, FnDefNode};
 
-use crate::descriptors::{
+use crate::hir::{
     function::{FnId, FnScopes},
     DescriptorDatabase,
 };
diff --git a/crates/ra_analysis/src/descriptors/function/mod.rs b/crates/ra_analysis/src/hir/function/mod.rs
similarity index 100%
rename from crates/ra_analysis/src/descriptors/function/mod.rs
rename to crates/ra_analysis/src/hir/function/mod.rs
diff --git a/crates/ra_analysis/src/descriptors/function/scope.rs b/crates/ra_analysis/src/hir/function/scope.rs
similarity index 100%
rename from crates/ra_analysis/src/descriptors/function/scope.rs
rename to crates/ra_analysis/src/hir/function/scope.rs
diff --git a/crates/ra_analysis/src/descriptors/mod.rs b/crates/ra_analysis/src/hir/mod.rs
similarity index 90%
rename from crates/ra_analysis/src/descriptors/mod.rs
rename to crates/ra_analysis/src/hir/mod.rs
index 7a1bcf4475..6bee2b5c41 100644
--- a/crates/ra_analysis/src/descriptors/mod.rs
+++ b/crates/ra_analysis/src/hir/mod.rs
@@ -1,3 +1,10 @@
+//! HIR (previsouly known as descriptors) provides a high-level OO acess to Rust
+//! code.
+//!
+//! The principal difference between HIR and syntax trees is that HIR is bound
+//! to a particular crate instance. That is, it has cfg flags and features
+//! applied. So, there relation between syntax and HIR is many-to-one.
+
 pub(crate) mod function;
 pub(crate) mod module;
 mod path;
@@ -12,8 +19,8 @@ use ra_syntax::{
 use crate::{
     FileId,
     db::SyntaxDatabase,
-    descriptors::function::{resolve_local_name, FnId, FnScopes},
-    descriptors::module::{
+    hir::function::{resolve_local_name, FnId, FnScopes},
+    hir::module::{
         ModuleId, ModuleTree, ModuleSource, ModuleDescriptor,
         nameres::{ItemMap, InputModuleItems, FileItems}
     },
diff --git a/crates/ra_analysis/src/descriptors/module/imp.rs b/crates/ra_analysis/src/hir/module/imp.rs
similarity index 99%
rename from crates/ra_analysis/src/descriptors/module/imp.rs
rename to crates/ra_analysis/src/hir/module/imp.rs
index 80892acb74..d8539ed856 100644
--- a/crates/ra_analysis/src/descriptors/module/imp.rs
+++ b/crates/ra_analysis/src/hir/module/imp.rs
@@ -9,7 +9,7 @@ use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
     db,
-    descriptors::DescriptorDatabase,
+    hir::DescriptorDatabase,
     input::{SourceRoot, SourceRootId},
     Cancelable, FileId, FileResolverImp,
 };
diff --git a/crates/ra_analysis/src/descriptors/module/mod.rs b/crates/ra_analysis/src/hir/module/mod.rs
similarity index 99%
rename from crates/ra_analysis/src/descriptors/module/mod.rs
rename to crates/ra_analysis/src/hir/module/mod.rs
index 78911d5d9c..f374a079f0 100644
--- a/crates/ra_analysis/src/descriptors/module/mod.rs
+++ b/crates/ra_analysis/src/hir/module/mod.rs
@@ -14,7 +14,7 @@ use relative_path::RelativePathBuf;
 
 use crate::{
     db::SyntaxDatabase, syntax_ptr::SyntaxPtr, FileId, FilePosition, Cancelable,
-    descriptors::{Path, PathKind, DescriptorDatabase},
+    hir::{Path, PathKind, DescriptorDatabase},
     input::SourceRootId,
     arena::{Arena, Id},
     loc2id::{DefLoc, DefId},
diff --git a/crates/ra_analysis/src/descriptors/module/nameres.rs b/crates/ra_analysis/src/hir/module/nameres.rs
similarity index 99%
rename from crates/ra_analysis/src/descriptors/module/nameres.rs
rename to crates/ra_analysis/src/hir/module/nameres.rs
index d2964f67f9..1ec85fbf25 100644
--- a/crates/ra_analysis/src/descriptors/module/nameres.rs
+++ b/crates/ra_analysis/src/hir/module/nameres.rs
@@ -31,7 +31,7 @@ use ra_syntax::{
 use crate::{
     Cancelable, FileId,
     loc2id::{DefId, DefLoc},
-    descriptors::{
+    hir::{
         Path, PathKind,
         DescriptorDatabase,
         module::{ModuleId, ModuleTree, ModuleSourceNode},
@@ -447,7 +447,7 @@ mod tests {
     use crate::{
         AnalysisChange,
         mock_analysis::{MockAnalysis, analysis_and_position},
-        descriptors::{DescriptorDatabase, module::ModuleDescriptor},
+        hir::{DescriptorDatabase, module::ModuleDescriptor},
         input::FilesDatabase,
 };
     use super::*;
diff --git a/crates/ra_analysis/src/descriptors/path.rs b/crates/ra_analysis/src/hir/path.rs
similarity index 100%
rename from crates/ra_analysis/src/descriptors/path.rs
rename to crates/ra_analysis/src/hir/path.rs
diff --git a/crates/ra_analysis/src/imp.rs b/crates/ra_analysis/src/imp.rs
index 8a41b31526..8d60f9af7e 100644
--- a/crates/ra_analysis/src/imp.rs
+++ b/crates/ra_analysis/src/imp.rs
@@ -19,7 +19,7 @@ use salsa::{Database, ParallelDatabase};
 use crate::{
     completion::{completions, CompletionItem},
     db::{self, FileSyntaxQuery, SyntaxDatabase},
-    descriptors::{
+    hir::{
         function::{FnDescriptor, FnId},
         module::{ModuleDescriptor, Problem},
         DeclarationDescriptor, DescriptorDatabase,
@@ -589,7 +589,7 @@ fn resolve_local_name(
     let fn_def = name_ref.syntax().ancestors().find_map(ast::FnDef::cast)?;
     let fn_id = FnId::get(db, file_id, fn_def);
     let scopes = db.fn_scopes(fn_id);
-    let scope_entry = crate::descriptors::function::resolve_local_name(name_ref, &scopes)?;
+    let scope_entry = crate::hir::function::resolve_local_name(name_ref, &scopes)?;
     let syntax = db.resolve_syntax_ptr(scope_entry.ptr().into_global(file_id));
     Some((scope_entry.name().clone(), syntax.range()))
 }
diff --git a/crates/ra_analysis/src/lib.rs b/crates/ra_analysis/src/lib.rs
index 0fbfd8a408..4659eb523a 100644
--- a/crates/ra_analysis/src/lib.rs
+++ b/crates/ra_analysis/src/lib.rs
@@ -19,14 +19,14 @@ macro_rules! ctry {
 }
 
 mod arena;
+mod syntax_ptr;
+mod input;
 mod db;
 mod loc2id;
-mod input;
 mod imp;
 mod completion;
-mod descriptors;
+mod hir;
 mod symbol_index;
-mod syntax_ptr;
 pub mod mock_analysis;
 
 use std::{fmt, sync::Arc};
@@ -42,7 +42,7 @@ use crate::{
 
 pub use crate::{
     completion::CompletionItem,
-    descriptors::function::FnDescriptor,
+    hir::function::FnDescriptor,
     input::{CrateGraph, CrateId, FileId, FileResolver},
 };
 pub use ra_editor::{
diff --git a/crates/ra_analysis/src/loc2id.rs b/crates/ra_analysis/src/loc2id.rs
index c7c799a91f..d42af4e0a0 100644
--- a/crates/ra_analysis/src/loc2id.rs
+++ b/crates/ra_analysis/src/loc2id.rs
@@ -9,8 +9,8 @@ use rustc_hash::FxHashMap;
 
 use crate::{
     FileId,
-    descriptors::FileItemId,
-    descriptors::module::ModuleId,
+    hir::FileItemId,
+    hir::module::ModuleId,
     syntax_ptr::SyntaxPtr,
     input::SourceRootId,
 };