So, No. of possible outcomes while tossing a coin $=2$ i.e., $1$ head or $1$ tail
We know that Probability = Number of favorable outcomes/ Total number of outcomes
P (getting head)$=1/2$
P (getting tail) $=1/2$
As we can see clearly that the probability of both the events are equal, these are called equally like events.
Hence, tossing a coin is considered to be a fair way of deciding which team should choose ends in a game of cricket.