diff --git a/README.md b/README.md
index f4ab876..1115da8 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,8 @@
 
 ## Creature Structure
 
-Each creature is represented as a matrix of blocks in a 2D grid world
+Each creature is represented as a matrix of blocks in a 2D grid, but all creatures and
+structures only occupy one block in the world matrix.
 
 There are three kinds of blocks:
 - neuron blocks
@@ -13,13 +14,14 @@ TODO: energy system
 
 ### Connection
 
-Each block is connected to every other adiacent block
+- Each block is connected to every other adiacent block (diagonals too), so each block has 9 connection weights.
 
 `source block output ->>>- * weight ->>>- destination block`
 
 - A connection has a weight, which is a floating point number.
 - The connection outputs its source block's current stored signal multiplied by the weight.
 - If the weight is `0`, then there's no connection
+- the weight is a floating point number between -1 and 1 included.
 
 ### Signals
 
@@ -42,13 +44,25 @@ They take an input signal and act by doing something, for example:
 
 ### Sensor (Input) blocks
 
-They give adiacent blocks a signal, for example:
+They give adiacent blocks a signal.
 
-- they communicate how far is the first block in a straight line
-- they communicate the amount of blocks in relation to blank spaces in an area
+Some examples:
+
+- they communicate how far is the first structure in a straight line
+- they communicate the amount of structures in relation to blank spaces in an area (popularity in an area)
 - they communicate the color/type/activity of the first block in a straight line
-- they communicate information about the presence of a particular kind of block in a direction
-- they communicate information about the creature itself, like integrity of adiacent blocks
+- they communicate information about the presence of a particular kind of structure in a direction
+- they communicate information about the structure itself, like integrity of adiacent blocks
+
+Generated signals are floating point numbers ranging from -1 to 1 included.
+
+### Combined (Input+Output) blocks
+
+They act as Sensor blocks and Action blocks at the same time.
+
+Examples:
+
+- a "mouth" block that can communicate wether food is available to eat and can receive eat commands at the same time
 
 ### Traversing the brain graph