A biome is an climate zone with specific height, light levels, vegetation, and types of blocks. Minecraft PE has 34 biomes in total and they are more or less with a few exceptions the same as those found in Minecraft PC. Listed below is a brief description of what you can expect from each of the different types of biome.
Snowy Biomes
Mainly snow and ice. The foliage and grass is a dark aqua-green.
Cold Beach
Cold Taiga
Cold Taiga (Mountainous)
Frozen River
Ice Plains
Ice Plains Spikes
Cold Biomes
These biomes are cold, but not cold enough to have snow everywhere. The foliage and grass is an aqua-green.
Stone Beach
Taiga
Extreme Hills
Extreme Hills M
Extreme Hills+
Extreme Hills+ M
Taiga M
Mega Taiga
Mega Spruce Taiga
Lush Biomes
These biomes tend to be warm and have flowers growing and are great for crop cultivation. The foliage and grass is a vibrant light green, except swamps and roofed forests, which have a dark green grass.
River
Beach
Plains
Sunflower Plains
Forest
Flower Forest
Swamp
Swamp M
Jungle
Jungle M
Jungle Edge
Jungle Edge M
Birch Forest
Birch Forest M
Birch Forest Hills M
Roofed Forest
Roofed Forest M
Mushroom Island
Mushroom Island Shore
Dry Biomes
It never rains in these biomes, they are hot and rarely contain any moisture or foliage. If there is foliage and grass it is an olive colour, except mesa biomes, which have brown grass.
Mesa
Mesa (Bryce)
Desert
Desert M
Plateau
Plateau M
Savannah
Savannah M
Neutral Biomes
These biomes are usually filled with water and have very little land exposed. Either that, or they have many variants that vary depending on their biome.
Ocean
Deep Ocean
Hills (Variants)
The video below is a showcase of the top five mesa biomes in Minecraft PE