These methods fall under the general class of one-step methods. The algoritm is rather simple. Suppose we have an initial value for the function $y(t)$ given by $$\begin{equation} y_0=y(t=t_0). \tag{10} \end{equation}$$ We are interested in solving a differential equation in a region in space $[a,b]$. We define a step $h$ by splitting the interval in $N$ sub intervals, so that we have $$\begin{equation} h=\frac{b-a}{N}. \tag{11} \end{equation}$$ With this step and the derivative of $y$ we can construct the next value of the function $y$ at $$\begin{equation} y_1=y(t_1=t_0+h), \tag{12} \end{equation}$$ and so forth.