Unicode defines 220 blocks of related characters.

Blocks

Basic Latin
Latin-1 Supplement
Latin Extended-A
Latin Extended-B
IPA Extensions
Spacing Modifier Letters
Combining Diacritical Marks
Greek and Coptic
Cyrillic
Cyrillic Supplement
Armenian
Hebrew
Arabic
Syriac
Arabic Supplement
Thaana
NKo
Samaritan
Mandaic
Arabic Extended-A
Devanagari
Bengali
Gurmukhi
Gujarati
Oriya
Tamil
Telugu
Kannada
Malayalam
Sinhala
Thai
Lao
Tibetan
Myanmar
Georgian
Hangul Jamo
Ethiopic
Ethiopic Supplement
Cherokee
Unified Canadian Aboriginal Syllabics
Ogham
Runic
Tagalog
Hanunoo
Buhid
Tagbanwa
Khmer
Mongolian
Unified Canadian Aboriginal Syllabics Extended
Limbu
Tai Le
New Tai Lue
Khmer Symbols
Buginese
Tai Tham
Balinese
Sundanese
Batak
Lepcha
Ol Chiki
Sundanese Supplement
Vedic Extensions
Phonetic Extensions
Phonetic Extensions Supplement
Combining Diacritical Marks Supplement
Latin Extended Additional
Greek Extended
General Punctuation
Superscripts and Subscripts
Currency Symbols
Combining Diacritical Marks for Symbols
Letterlike Symbols
Number Forms
Arrows
Mathematical Operators
Miscellaneous Technical
Control Pictures
Optical Character Recognition
Enclosed Alphanumerics
Box Drawing
Block Elements
Geometric Shapes
Miscellaneous Symbols
Dingbats
Miscellaneous Mathematical Symbols-A
Supplemental Arrows-A
Braille Patterns
Supplemental Arrows-B
Miscellaneous Mathematical Symbols-B
Supplemental Mathematical Operators
Miscellaneous Symbols and Arrows
Glagolitic
Latin Extended-C
Coptic
Georgian Supplement
Tifinagh
Ethiopic Extended
Cyrillic Extended-A
Supplemental Punctuation
CJK Radicals Supplement
Kangxi Radicals
Ideographic Description Characters
CJK Symbols and Punctuation
Hiragana
Katakana
Bopomofo
Hangul Compatibility Jamo
Kanbun
Bopomofo Extended
CJK Strokes
Katakana Phonetic Extensions
Enclosed CJK Letters and Months
CJK Compatibility
CJK Unified Ideographs Extension A
Yijing Hexagram Symbols
CJK Unified Ideographs
Yi Syllables
Yi Radicals
Lisu
Vai
Cyrillic Extended-B
Bamum
Modifier Tone Letters
Latin Extended-D
Syloti Nagri
Common Indic Number Forms
Phags-pa
Saurashtra
Devanagari Extended
Kayah Li
Rejang
Hangul Jamo Extended-A
Javanese
Cham
Myanmar Extended-A
Tai Viet
Meetei Mayek Extensions
Ethiopic Extended-A
Meetei Mayek
Hangul Syllables
Hangul Jamo Extended-B
High Surrogates
High Private Use Surrogates
Low Surrogates
Private Use Area
CJK Compatibility Ideographs
Alphabetic Presentation Forms
Arabic Presentation Forms-A
Variation Selectors
Vertical Forms
Combining Half Marks
CJK Compatibility Forms
Small Form Variants
Arabic Presentation Forms-B
Halfwidth and Fullwidth Forms
Specials
Linear B Syllabary
Linear B Ideograms
Aegean Numbers
Ancient Greek Numbers
Ancient Symbols
Phaistos Disc
Lycian
Carian
Old Italic
Gothic
Ugaritic
Old Persian
Deseret
Shavian
Osmanya
Cypriot Syllabary
Imperial Aramaic
Phoenician
Lydian
Meroitic Hieroglyphs
Meroitic Cursive
Kharoshthi
Old South Arabian
Avestan
Inscriptional Parthian
Inscriptional Pahlavi
Old Turkic
Rumi Numeral Symbols
Brahmi
Kaithi
Sora Sompeng
Chakma
Sharada
Takri
Cuneiform
Cuneiform Numbers and Punctuation
Egyptian Hieroglyphs
Bamum Supplement
Miao
Kana Supplement
Byzantine Musical Symbols
Musical Symbols
Ancient Greek Musical Notation
Tai Xuan Jing Symbols
Counting Rod Numerals
Mathematical Alphanumeric Symbols
Arabic Mathematical Alphabetic Symbols
Mahjong Tiles
Domino Tiles
Playing Cards
Enclosed Alphanumeric Supplement
Enclosed Ideographic Supplement
Miscellaneous Symbols And Pictographs
Emoticons
Transport And Map Symbols
Alchemical Symbols
CJK Unified Ideographs Extension B
CJK Unified Ideographs Extension C
CJK Unified Ideographs Extension D
CJK Compatibility Ideographs Supplement
Tags
Variation Selectors Supplement
Supplementary Private Use Area-A
Supplementary Private Use Area-B