Logistic regression likelihood estimation(video)

In the “likelihood estimation and loss” video
1.what does the likelihood function mean?
2.How does maximizing the likelihood function gives the optimal set of theta parameters for the classification boundry?

In MLE we try to find that parameter which is most ‘likely’ to be the correct parameter, which gives the maximum value of the likelihood function

For more intuitive explanations i would suggest you reading the two posts below :

https://link.medium.com/vb29Vd8MGT

https://link.medium.com/7wgzxq7NGT

Thanks for the posts I have started to understand likelihood better but I still couldn’t understand:
how maximizing the likelihood function gives the optimal parameters for the boundary line to classify the datasets correctly?

We are using -ve of likelihood as our cost function.
Minimizing our cost function is same as maximizing the likelihood.
And minimizing cost function leads to better decision boundary

In linear regression cost function meant deviation from the data and minimizing the deviation gives the right set of parameters.
But in logistic regression what does the cost function(-ve likelihood) mean it certainly doesn’t seem to be deviation from the true value.

P.s-To me likelihood is some what like probability(please correct me if I am wrong)

The derivation in this article is quite intuitive :

Generally probability and likelihood are used exchangeably