diff --git a/common/bytes.go b/common/bytes.go
index e2adc80059..2892cc035a 100644
--- a/common/bytes.go
+++ b/common/bytes.go
@@ -19,6 +19,7 @@ package common
 
 import "encoding/hex"
 
+// ToHex returns string representation of b and either prepends '0x' or initializes value of '0'.
 func ToHex(b []byte) string {
 	hex := Bytes2Hex(b)
 	// Prefer output of "0x0" instead of "0x"
@@ -28,6 +29,7 @@ func ToHex(b []byte) string {
 	return "0x" + hex
 }
 
+//FromHex returns bytes of s after removing prefix, or prepends 0 if s has odd length.
 func FromHex(s string) []byte {
 	if len(s) > 1 {
 		if s[0:2] == "0x" || s[0:2] == "0X" {
@@ -40,9 +42,7 @@ func FromHex(s string) []byte {
 	return Hex2Bytes(s)
 }
 
-// Copy bytes
-//
-// Returns an exact copy of the provided bytes
+// CopyBytes returns an exact copy of the provided bytes
 func CopyBytes(b []byte) (copiedBytes []byte) {
 	if b == nil {
 		return nil
@@ -53,14 +53,17 @@ func CopyBytes(b []byte) (copiedBytes []byte) {
 	return
 }
 
+// hasHexPrefix validates str begins with '0x' or '0X'.
 func hasHexPrefix(str string) bool {
 	return len(str) >= 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X')
 }
 
+// isHexCharacter returns bool of c being a valid hexadecimal.
 func isHexCharacter(c byte) bool {
 	return ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')
 }
 
+// isHex validates whether each byte is valid hexadecimal string.
 func isHex(str string) bool {
 	if len(str)%2 != 0 {
 		return false
@@ -73,16 +76,19 @@ func isHex(str string) bool {
 	return true
 }
 
+//Bytes2Hex returns the hexadecimal encoding of d.
 func Bytes2Hex(d []byte) string {
 	return hex.EncodeToString(d)
 }
 
+// Hex2Bytes returns the bytes represented by the hexadecimal string str.
 func Hex2Bytes(str string) []byte {
 	h, _ := hex.DecodeString(str)
 
 	return h
 }
 
+// Hex2BytesFixed returns bytes of a specified fixed length flen.
 func Hex2BytesFixed(str string, flen int) []byte {
 	h, _ := hex.DecodeString(str)
 	if len(h) == flen {
@@ -96,6 +102,7 @@ func Hex2BytesFixed(str string, flen int) []byte {
 	return hh
 }
 
+// RightPadBytes copies slice into a byte slice of length l.
 func RightPadBytes(slice []byte, l int) []byte {
 	if l <= len(slice) {
 		return slice
@@ -107,6 +114,7 @@ func RightPadBytes(slice []byte, l int) []byte {
 	return padded
 }
 
+// LeftPadBytes copies via inverted index slice into a byte slice of length l.
 func LeftPadBytes(slice []byte, l int) []byte {
 	if l <= len(slice) {
 		return slice
diff --git a/common/path.go b/common/path.go
index bd8da86e74..f848f47f2d 100644
--- a/common/path.go
+++ b/common/path.go
@@ -30,6 +30,7 @@ func MakeName(name, version string) string {
 	return fmt.Sprintf("%s/v%s/%s/%s", name, version, runtime.GOOS, runtime.Version())
 }
 
+// FileExist checks if a file exists at filePath and returns a bool.
 func FileExist(filePath string) bool {
 	_, err := os.Stat(filePath)
 	if err != nil && os.IsNotExist(err) {
@@ -39,6 +40,7 @@ func FileExist(filePath string) bool {
 	return true
 }
 
+// AbsolutePath returns Datadir + filename, or filename if it is absolute.
 func AbsolutePath(Datadir string, filename string) string {
 	if filepath.IsAbs(filename) {
 		return filename
diff --git a/common/types.go b/common/types.go
index 0b94fb2c25..1cb0ce170c 100644
--- a/common/types.go
+++ b/common/types.go
@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto/sha3"
 )
 
+// Sets global constants.
 const (
 	HashLength    = 32
 	AddressLength = 20
@@ -42,19 +43,30 @@ var (
 // Hash represents the 32 byte Keccak256 hash of arbitrary data.
 type Hash [HashLength]byte
 
+// BytesToHash sets b to hash. If b is larger than len(h), 'b' will be cropped (from the left).
 func BytesToHash(b []byte) Hash {
 	var h Hash
 	h.SetBytes(b)
 	return h
 }
-func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
-func HexToHash(s string) Hash   { return BytesToHash(FromHex(s)) }
 
-// Get the string representation of the underlying hash
-func (h Hash) Str() string   { return string(h[:]) }
+// BigToHash sets byte representation of b to hash. If b is larger than len(h), 'b' will be cropped (from the left).
+func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
+
+// HexToHash sets byte representation of s to hash. If b is larger than len(h), 'b' will be cropped (from the left).
+func HexToHash(s string) Hash { return BytesToHash(FromHex(s)) }
+
+// Str gets the string representation of the underlying hash.
+func (h Hash) Str() string { return string(h[:]) }
+
+// Bytes gets the byte representation of the underlying hash.
 func (h Hash) Bytes() []byte { return h[:] }
+
+// Big gets the big integer representation of the underlying hash.
 func (h Hash) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }
-func (h Hash) Hex() string   { return hexutil.Encode(h[:]) }
+
+// Hex gets the hex representation of the underlying hash.
+func (h Hash) Hex() string { return hexutil.Encode(h[:]) }
 
 // TerminalString implements log.TerminalStringer, formatting a string for console
 // output during logging.
@@ -89,7 +101,7 @@ func (h Hash) MarshalText() ([]byte, error) {
 	return hexutil.Bytes(h[:]).MarshalText()
 }
 
-// Sets the hash to the value of b. If b is larger than len(h), 'b' will be cropped (from the left).
+// SetBytes sets the hash to the value of b. If b is larger than len(h), 'b' will be cropped (from the left).
 func (h *Hash) SetBytes(b []byte) {
 	if len(b) > len(h) {
 		b = b[len(b)-HashLength:]
@@ -98,10 +110,10 @@ func (h *Hash) SetBytes(b []byte) {
 	copy(h[HashLength-len(b):], b)
 }
 
-// Set string `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
+// SetString sets `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
 func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }
 
-// Sets h to other
+// Set sets h to other
 func (h *Hash) Set(other Hash) {
 	for i, v := range other {
 		h[i] = v
@@ -117,6 +129,7 @@ func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
 	return reflect.ValueOf(h)
 }
 
+// EmptyHash clears h of values.
 func EmptyHash(h Hash) bool {
 	return h == Hash{}
 }
@@ -139,13 +152,18 @@ func (h UnprefixedHash) MarshalText() ([]byte, error) {
 // Address represents the 20 byte address of an Ethereum account.
 type Address [AddressLength]byte
 
+// BytesToAddress returns Address with value b. If b is larger than len(h), 'b' will be cropped (from the left).
 func BytesToAddress(b []byte) Address {
 	var a Address
 	a.SetBytes(b)
 	return a
 }
+
+//BigToAddress returns Address with byte values of b. If b is larger than len(h), 'b' will be cropped (from the left).
 func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }
-func HexToAddress(s string) Address   { return BytesToAddress(FromHex(s)) }
+
+//HexToAddress returns Address with byte values of s. If s is larger than len(h), 's' will be cropped (from the left).
+func HexToAddress(s string) Address { return BytesToAddress(FromHex(s)) }
 
 // IsHexAddress verifies whether a string can represent a valid hex-encoded
 // Ethereum address or not.
@@ -156,11 +174,17 @@ func IsHexAddress(s string) bool {
 	return len(s) == 2*AddressLength && isHex(s)
 }
 
-// Get the string representation of the underlying address
-func (a Address) Str() string   { return string(a[:]) }
+// Str gets the string representation of the underlying address.
+func (a Address) Str() string { return string(a[:]) }
+
+// Bytes gets the string representation of the underlying address.
 func (a Address) Bytes() []byte { return a[:] }
+
+// Big gets the string representation of the underlying address.
 func (a Address) Big() *big.Int { return new(big.Int).SetBytes(a[:]) }
-func (a Address) Hash() Hash    { return BytesToHash(a[:]) }
+
+// Hash gets the string representation of the underlying address.
+func (a Address) Hash() Hash { return BytesToHash(a[:]) }
 
 // Hex returns an EIP55-compliant hex string representation of the address.
 func (a Address) Hex() string {
@@ -195,7 +219,7 @@ func (a Address) Format(s fmt.State, c rune) {
 	fmt.Fprintf(s, "%"+string(c), a[:])
 }
 
-// Sets the address to the value of b. If b is larger than len(a) it will panic
+// SetBytes sets the address to the value of b. If b is larger than len(a) it will panic
 func (a *Address) SetBytes(b []byte) {
 	if len(b) > len(a) {
 		b = b[len(b)-AddressLength:]
@@ -203,10 +227,10 @@ func (a *Address) SetBytes(b []byte) {
 	copy(a[AddressLength-len(b):], b)
 }
 
-// Set string `s` to a. If s is larger than len(a) it will panic
+// SetString sets `s` to a. If s is larger than len(a) it will panic
 func (a *Address) SetString(s string) { a.SetBytes([]byte(s)) }
 
-// Sets a to other
+// Set sets a to other
 func (a *Address) Set(other Address) {
 	for i, v := range other {
 		a[i] = v
@@ -228,7 +252,7 @@ func (a *Address) UnmarshalJSON(input []byte) error {
 	return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
 }
 
-// UnprefixedHash allows marshaling an Address without 0x prefix.
+// UnprefixedAddress allows marshaling an Address without 0x prefix.
 type UnprefixedAddress Address
 
 // UnmarshalText decodes the address from hex. The 0x prefix is optional.