diff --git a/types/compare.go b/types/compare.go
index e60dc503bc3..c903bbb5c9f 100644
--- a/types/compare.go
+++ b/types/compare.go
@@ -18,6 +18,7 @@ package types
 
 import "github.com/dgraph-io/dgraph/x"
 
+// CompareVals compares two values using the given comparison type.
 // Should be used only in filtering arg1 by comparing with arg2.
 // arg2 is reference Val to which arg1 is compared.
 func CompareVals(op string, arg1, arg2 Val) bool {
diff --git a/types/conversion.go b/types/conversion.go
index 42a1f3ef296..7429e0b2bf1 100644
--- a/types/conversion.go
+++ b/types/conversion.go
@@ -519,6 +519,7 @@ func cantConvert(from TypeID, to TypeID) error {
 	return errors.Errorf("Cannot convert %s to type %s", from.Name(), to.Name())
 }
 
+// MarshalJSON makes Val satisfy the json.Marshaler interface.
 func (v Val) MarshalJSON() ([]byte, error) {
 	switch v.Tid {
 	case IntID:
diff --git a/types/facets/facet_types.go b/types/facets/facet_types.go
index 6850599e429..f0155e91228 100644
--- a/types/facets/facet_types.go
+++ b/types/facets/facet_types.go
@@ -19,13 +19,19 @@ package facets
 import "github.com/dgraph-io/dgo/protos/api"
 
 const (
-	IntID      = TypeID(api.Facet_INT)
-	FloatID    = TypeID(api.Facet_FLOAT)
-	BoolID     = TypeID(api.Facet_BOOL)
+	// IntID represents the integer type.
+	IntID = TypeID(api.Facet_INT)
+	// FloatID represents the floating-point number type.
+	FloatID = TypeID(api.Facet_FLOAT)
+	// BoolID represents the boolean type.
+	BoolID = TypeID(api.Facet_BOOL)
+	// DateTimeID represents the datetime type.
 	DateTimeID = TypeID(api.Facet_DATETIME)
-	StringID   = TypeID(api.Facet_STRING)
+	// StringID represents the string type.
+	StringID = TypeID(api.Facet_STRING)
 )
 
+// TypeID represents the type of a facet.
 type TypeID api.Facet_ValType
 
 // ValTypeForTypeID gives api.Facet_ValType for given TypeID
diff --git a/types/facets/utils.go b/types/facets/utils.go
index 712bfcc0224..e410f763d92 100644
--- a/types/facets/utils.go
+++ b/types/facets/utils.go
@@ -30,7 +30,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-// Sorts And validates the facets.
+// SortAndValidate sorts And validates the facets.
 func SortAndValidate(fs []*api.Facet) error {
 	if len(fs) == 0 {
 		return nil
@@ -148,6 +148,7 @@ func FacetFor(key, val string) (*api.Facet, error) {
 	return facet, err
 }
 
+// ToBinary converts the given value into a binary value.
 func ToBinary(key string, value interface{}, sourceType api.Facet_ValType) (
 	*api.Facet, error) {
 	// convert facet val interface{} to binary
diff --git a/types/password.go b/types/password.go
index 9233044896b..70978fbf3be 100644
--- a/types/password.go
+++ b/types/password.go
@@ -26,6 +26,7 @@ const (
 	pwdLenLimit = 6
 )
 
+// Encrypt encrypts the given plain-text password.
 func Encrypt(plain string) (string, error) {
 	if len(plain) < pwdLenLimit {
 		return "", errors.Errorf("Password too short, i.e. should have at least 6 chars")
@@ -39,6 +40,7 @@ func Encrypt(plain string) (string, error) {
 	return string(encrypted), nil
 }
 
+// VerifyPassword checks that the plain-text password matches the encrypted password.
 func VerifyPassword(plain, encrypted string) error {
 	if len(plain) < pwdLenLimit || len(encrypted) == 0 {
 		return errors.Errorf("Invalid password/crypted string")
diff --git a/types/s2index.go b/types/s2index.go
index 042729186f8..1105b3b9496 100644
--- a/types/s2index.go
+++ b/types/s2index.go
@@ -38,8 +38,8 @@ func parentCoverTokens(parents s2.CellUnion, cover s2.CellUnion) []string {
 	return tokens
 }
 
-// IndexTokens returns the tokens to be used in a geospatial index for the given geometry. If the
-// geometry is not supported it returns an error.
+// IndexGeoTokens returns the tokens to be used in a geospatial index for the
+// given geometry. If the geometry is not supported it returns an error.
 func IndexGeoTokens(g geom.T) ([]string, error) {
 	parents, cover, err := indexCells(g)
 	if err != nil {
diff --git a/types/scalar_types.go b/types/scalar_types.go
index 38c7afaa5ee..5c75fbcc316 100644
--- a/types/scalar_types.go
+++ b/types/scalar_types.go
@@ -30,16 +30,27 @@ const nanoSecondsInSec = 1000000000
 // data. When adding a new type *always* add to the end of this list.
 // Never delete anything from this list even if it becomes unused.
 const (
-	DefaultID   = TypeID(pb.Posting_DEFAULT)
-	BinaryID    = TypeID(pb.Posting_BINARY)
-	IntID       = TypeID(pb.Posting_INT)
-	FloatID     = TypeID(pb.Posting_FLOAT)
-	BoolID      = TypeID(pb.Posting_BOOL)
-	DateTimeID  = TypeID(pb.Posting_DATETIME)
-	GeoID       = TypeID(pb.Posting_GEO)
-	UidID       = TypeID(pb.Posting_UID)
-	PasswordID  = TypeID(pb.Posting_PASSWORD)
-	StringID    = TypeID(pb.Posting_STRING)
+	// DefaultID represents the default type.
+	DefaultID = TypeID(pb.Posting_DEFAULT)
+	// BinaryID represents the binary data type.
+	BinaryID = TypeID(pb.Posting_BINARY)
+	// IntID represents the integer type.
+	IntID = TypeID(pb.Posting_INT)
+	// FloatID represents the floating-point number type.
+	FloatID = TypeID(pb.Posting_FLOAT)
+	// FloatID represents the boolean type.
+	BoolID = TypeID(pb.Posting_BOOL)
+	// DateTimeID represents the datetime type.
+	DateTimeID = TypeID(pb.Posting_DATETIME)
+	// GeoID represents the geo-location data type.
+	GeoID = TypeID(pb.Posting_GEO)
+	// UidID represents the uid type.
+	UidID = TypeID(pb.Posting_UID)
+	// PasswordID represents the password type.
+	PasswordID = TypeID(pb.Posting_PASSWORD)
+	// StringID represents the string type.
+	StringID = TypeID(pb.Posting_STRING)
+	// UndefinedID represents the undefined type.
 	UndefinedID = TypeID(100)
 )
 
@@ -56,12 +67,15 @@ var typeNameMap = map[string]TypeID{
 	"password": PasswordID,
 }
 
+// TypeID represents the type of the data.
 type TypeID pb.Posting_ValType
 
+// Enum takes a TypeID value and returns the corresponding ValType enum value.
 func (t TypeID) Enum() pb.Posting_ValType {
 	return pb.Posting_ValType(t)
 }
 
+// Name returns the name of the type.
 func (t TypeID) Name() string {
 	switch t {
 	case DefaultID:
@@ -115,10 +129,12 @@ func TypeForName(name string) (TypeID, bool) {
 	return t, ok
 }
 
+// IsScalar returns whether the type is a scalar type.
 func (t TypeID) IsScalar() bool {
 	return t != UidID
 }
 
+// IsNumber returns whether the type is a number type.
 func (t TypeID) IsNumber() bool {
 	return t == IntID || t == FloatID
 }
diff --git a/types/sort.go b/types/sort.go
index 65eb5e1b899..6ed772fac4b 100644
--- a/types/sort.go
+++ b/types/sort.go
@@ -80,7 +80,8 @@ func (s byValue) Less(i, j int) bool {
 	return false
 }
 
-// Sort sorts the given array in-place.
+// SortWithFacet sorts the given array in-place and considers the given facets to calculate
+// the proper ordering.
 func SortWithFacet(v [][]Val, ul *pb.List, l []*pb.Facets, desc []bool) error {
 	if len(v) == 0 || len(v[0]) == 0 {
 		return nil